Read error on stream <IP-addr>:443 after reading 5005 and writing 461 bytes: Operation timed out (os error 60).

[ygguser]

It seems that the censorship authorities have learned how to block DeltaСhat by signatures again.
The connection to the servers is not established.

DeltaChat v2.53.0

Storage Usage:
[Blob Directory Size]: 145.25 MiB
[Database Size]: 4.04 MiB
[Largest Tables]:
   msgs:                  1.74 MiB,   4864 rows
   imap:                   364 KiB,   4849 rows
   tokens:                  32 KiB,    667 rows
   msgs_mdns:               16 KiB,    642 rows
   transports:               4 KiB,      1 rows
   tls_spki:                 4 KiB,      1 rows
   stats_sending_enabled_events:      4 KiB,      0 rows
   stats_sending_disabled_events:      4 KiB,      0 rows
   stats_securejoin_uipaths:      4 KiB,      0 rows
   stats_securejoin_sources:      4 KiB,      0 rows
[Webxdc With Biggest Status Update Space Usage]:


[16.07.2026, 13:46] 💙 ➡️ didFinishLaunchingWithOptions
[16.07.2026, 13:46] 💙 ➡️ event emitter started
[16.07.2026, 13:46] 💙 [2] src/key.rs:133: Converting secret key to public key.
[16.07.2026, 13:46] 💙 [2] src/securejoin.rs:196: Generated QR code.
[16.07.2026, 13:46] 💙 [2] src/securejoin.rs:196: Generated QR code.
[16.07.2026, 13:46] 💙 ⏰ getChatlist: 0.0034259557723999023 s
[16.07.2026, 13:46] 💙 [2] src/chat.rs:4827: Device-message update_2_3_ios already added.
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:68: starting IO
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:347: Starting inbox loop.
[16.07.2026, 13:46] 💙 [1] src/location.rs:736: Location loop is waiting for 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:367: Transport 1: Preparing new IMAP session for inbox.
[16.07.2026, 13:46] 💙 [1] src/imap.rs:340: Connecting to IMAP server.
[16.07.2026, 13:46] 💙 [1] src/contact.rs:2158: Recently seen loop waiting for 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:549: Starting SMTP loop.
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:706: scheduler is running
[16.07.2026, 13:46] 💙 📡[1] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:68: starting IO
[16.07.2026, 13:46] 💙 📡[1] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:347: Starting inbox loop.
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:367: Transport 1: Preparing new IMAP session for inbox.
[16.07.2026, 13:46] 💙 [2] src/imap.rs:340: Connecting to IMAP server.
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:549: Starting SMTP loop.
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:706: scheduler is running
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:993:tls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:140: No memory-cached DNS resolution for chat.example.com available, waiting for the resolver.
[16.07.2026, 13:46] 💙 [2] src/location.rs:736: Location loop is waiting for 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [2] src/contact.rs:2158: Recently seen loop waiting for 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [1] src/ephemeral.rs:614: Ephemeral loop waiting for deletion in 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [2] src/ephemeral.rs:614: Ephemeral loop waiting for deletion in 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [2] src/ephemeral.rs:614: Ephemeral loop waiting for deletion in 24h 0m 0s or interrupt
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:993:tls.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:140: No memory-cached DNS resolution for dchat.twinkle.lol available, waiting for the resolver.
[16.07.2026, 13:46] 💙 [2] src/chat.rs:2885: Message Msg#4900 will be sent in one shot (no pre- and post-message). Size: 3.24 KiB.
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:993).
[16.07.2026, 13:46] 💙 [1] src/smtp.rs:522: Selected rows from SMTP queue: [].
[16.07.2026, 13:46] 💙 [1] src/smtp.rs:639: Sending MDNs.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:522: Selected rows from SMTP queue: [347].
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:589: SMTP fake idle started.
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 📡[1] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:133: SMTP trying to connect to chat.example.com:443:tls.
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:617: SMTP has no messages to retry, waiting for interrupt.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/smtp/connect.rs:109: Attempting SMTP connection to chat.example.com (108.183.99.44:443).
[16.07.2026, 13:46] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:993).
[16.07.2026, 13:46] 💙 ☎️ voIP token received
[16.07.2026, 13:46] 💙 network: reachable WiFi
[16.07.2026, 13:46] 💙 ➡️ applicationDidBecomeActive
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:621: SMTP fake idle interrupted.
[16.07.2026, 13:46] 💙 [2] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 💙 Notifications: Permission granted
[16.07.2026, 13:46] 💙 Notifications: Permission granted
[16.07.2026, 13:46] 💙 [1] src/smtp.rs:522: Selected rows from SMTP queue: [].
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:46] 💙 [1] src/smtp.rs:639: Sending MDNs.
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:143:starttls.
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:589: SMTP fake idle started.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 📡[1] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [1] src/scheduler.rs:617: SMTP has no messages to retry, waiting for interrupt.
[16.07.2026, 13:46] 💙 Notifications: Registered
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:143).
[16.07.2026, 13:46] 💙 [1] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 🧡 [1] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:46] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:443:tls.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:134: Using memory-cached DNS resolution for dchat.twinkle.lol.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:46] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:443).
[16.07.2026, 13:46] 💙 [1] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 🧡 [1] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:46] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:143:starttls.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:134: Using memory-cached DNS resolution for dchat.twinkle.lol.
[16.07.2026, 13:46] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:46] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:143).
[16.07.2026, 13:46] 🧡 [2] src/imap/client.rs:151: IMAP failed to connect to chat.example.com (108.183.99.44:143): Connection to 108.183.99.44:143 failed: Operation timed out (os error 60).
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:368: IMAP failed to connect to chat.example.com:143:starttls: All connection attempts failed: Connection to 108.183.99.44:143 failed: Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:443:tls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:443).
[16.07.2026, 13:46] 💙 [2] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 🧡 [2] src/smtp.rs:148: SMTP failed to connect and authenticate: Failed to send EHLO command: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:133: SMTP trying to connect to chat.example.com:465:tls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/smtp/connect.rs:109: Attempting SMTP connection to chat.example.com (108.183.99.44:465).
[16.07.2026, 13:46] 🧡 [2] Read error on stream 108.183.99.44:443 after reading 5005 and writing 461 bytes: Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 🧡 [2] src/scheduler.rs:373: Transport 1: Failed to prepare inbox connection: CAPABILITY command error: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:367: Transport 1: Preparing new IMAP session for inbox.
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:321: IMAP got rate limited, waiting for 0h 0m 33s until can connect.
[16.07.2026, 13:46] 💙 [2] src/imap.rs:333: Connecting to IMAP without waiting for ratelimit due to interrupt.
[16.07.2026, 13:46] 💙 [2] src/imap.rs:340: Connecting to IMAP server.
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:443:tls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:443).
[16.07.2026, 13:46] 💙 [2] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:993:tls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:993).
[16.07.2026, 13:46] 💙 [2] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:46] 💙 [2] src/imap.rs:355: IMAP trying to connect to chat.example.com:143:starttls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/imap/client.rs:122: Attempting IMAP connection to chat.example.com (108.183.99.44:143).
[16.07.2026, 13:46] 🧡 [2] src/imap/client.rs:151: IMAP failed to connect to chat.example.com (108.183.99.44:143): Connection to 108.183.99.44:143 failed: Operation timed out (os error 60).
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:368: IMAP failed to connect to chat.example.com:143:starttls: All connection attempts failed: Connection to 108.183.99.44:143 failed: Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 🧡 [2] src/scheduler.rs:373: Transport 1: Failed to prepare inbox connection: Не удалось авторизоваться как "wxdlzda4rzjgm0peu@chat.example.com". Убедитесь, что адрес электронной почты и пароль введены правильно. (no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)")).
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:367: Transport 1: Preparing new IMAP session for inbox.
[16.07.2026, 13:46] 🧡 [2] src/imap.rs:321: IMAP got rate limited, waiting for 0h 0m 52s until can connect.
[16.07.2026, 13:46] 🧡 [2] src/smtp.rs:148: SMTP failed to connect and authenticate: Failed to send EHLO command: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:133: SMTP trying to connect to chat.example.com:587:starttls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/smtp/connect.rs:109: Attempting SMTP connection to chat.example.com (108.183.99.44:587).
[16.07.2026, 13:46] 💙 ⬅️ applicationWillResignActive
[16.07.2026, 13:46] 💙 ⬅️ registering background task
[16.07.2026, 13:46] 💙 ➡️ applicationDidBecomeActive
[16.07.2026, 13:46] 💙 ⬅️ no longer in background
[16.07.2026, 13:46] 💙 ⬅️ applicationWillResignActive
[16.07.2026, 13:46] 💙 ⬅️ registering background task
[16.07.2026, 13:46] 💙 ➡️ applicationDidBecomeActive
[16.07.2026, 13:46] 💙 ⬅️ no longer in background
[16.07.2026, 13:46] 🧡 [2] src/smtp.rs:148: SMTP failed to connect and authenticate: Failed to send EHLO command: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:46] 🧡 [2] src/scheduler.rs:567: send_smtp_messages failed: Failed to send message: SMTP connection failure: Failed to send EHLO command: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:589: SMTP fake idle started.
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:601: SMTP has messages to retry, planning to retry 30 seconds later.
[16.07.2026, 13:46] 💙 [2] src/scheduler.rs:621: SMTP fake idle interrupted.
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:522: Selected rows from SMTP queue: [347].
[16.07.2026, 13:46] 💙 📡[2] connectivity changed
[16.07.2026, 13:46] 💙 [2] src/smtp.rs:133: SMTP trying to connect to chat.example.com:587:starttls.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:46] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:46] 💙 [2] src/smtp/connect.rs:109: Attempting SMTP connection to chat.example.com (108.183.99.44:587).
[16.07.2026, 13:47] 🧡 [1] Read error on stream 109.234.38.124:143 after reading 0 and writing 0 bytes: timed out.
[16.07.2026, 13:47] 🧡 [1] src/imap/client.rs:151: IMAP failed to connect to dchat.twinkle.lol (109.234.38.124:143): timed out.
[16.07.2026, 13:47] 🧡 [1] src/imap.rs:368: IMAP failed to connect to dchat.twinkle.lol:143:starttls: All connection attempts failed: timed out.
[16.07.2026, 13:47] 💙 📡[1] connectivity changed
[16.07.2026, 13:47] 🧡 [1] src/scheduler.rs:373: Transport 1: Failed to prepare inbox connection: Не удалось авторизоваться как "f546z74c7@dchat.twinkle.lol". Убедитесь, что адрес электронной почты и пароль введены правильно. (no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)")).
[16.07.2026, 13:47] 💙 [1] src/scheduler.rs:367: Transport 1: Preparing new IMAP session for inbox.
[16.07.2026, 13:47] 💙 [1] src/imap.rs:340: Connecting to IMAP server.
[16.07.2026, 13:47] 💙 📡[1] connectivity changed
[16.07.2026, 13:47] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:443:tls.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:134: Using memory-cached DNS resolution for dchat.twinkle.lol.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:47] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:443).
[16.07.2026, 13:47] 💙 [1] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:47] 🧡 [1] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:47] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:993:tls.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:134: Using memory-cached DNS resolution for dchat.twinkle.lol.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:47] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:993).
[16.07.2026, 13:47] 💙 [1] src/imap.rs:393: Logging into IMAP server with LOGIN.
[16.07.2026, 13:47] 🧡 [1] src/imap.rs:444: IMAP failed to login: no response: code: None, info: Some("[UNAVAILABLE] Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10)").
[16.07.2026, 13:47] 💙 [1] src/imap.rs:355: IMAP trying to connect to dchat.twinkle.lol:143:starttls.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:134: Using memory-cached DNS resolution for dchat.twinkle.lol.
[16.07.2026, 13:47] 💙 [1] src/net/dns.rs:180: Resolved dchat.twinkle.lol into 109.234.38.124.
[16.07.2026, 13:47] 💙 [1] src/imap/client.rs:122: Attempting IMAP connection to dchat.twinkle.lol (109.234.38.124:143).
[16.07.2026, 13:47] 💙 ⬅️ applicationWillResignActive
[16.07.2026, 13:47] 💙 ⬅️ registering background task
[16.07.2026, 13:47] 💙 ➡️ applicationDidBecomeActive
[16.07.2026, 13:47] 💙 ⬅️ no longer in background
[16.07.2026, 13:47] 🧡 [2] src/smtp.rs:148: SMTP failed to connect and authenticate: Failed to send EHLO command: io: Operation timed out (os error 60): Operation timed out (os error 60).
[16.07.2026, 13:47] 💙 [2] src/smtp.rs:133: SMTP trying to connect to chat.example.com:465:tls.
[16.07.2026, 13:47] 💙 [2] src/net/dns.rs:134: Using memory-cached DNS resolution for chat.example.com.
[16.07.2026, 13:47] 💙 [2] src/net/dns.rs:180: Resolved chat.example.com into 108.183.99.44.
[16.07.2026, 13:47] 💙 [2] src/smtp/connect.rs:109: Attempting SMTP connection to chat.example.com (108.183.99.44:465).

[aryzhkov]

I found that if you go to Settings -> Advanced -> Relays, open a relay for editing (on a phone, by long-pressing it), and then select "Accept invalid certificates" at the bottom in the Certificate Checks section, the connection is established. So it's likely that they blocked something during the certificate verification process.

And this probably needs to be fixed in the Deltachat app itself, rather than on the Chatmail server.

[JoeMcNuggets]

Probably dynamic changing of JA3 signature could help to bypass TLS-fingerprinting detector.

Somehow ByeDPI with a set of TCP-desync and packet fragmentation strategies helps (as for me) to bypass that detection too (I suppose that SNI padding is the most helpful part of that strategy)

[ygguser]

It works again after the last update.