TCP connection stalls when talking to specific SMTP mail server
|Reported by:||zooey||Owned by:||axeld|
|Component:||Network & Internet/TCP||Version:||R1/Development|
|Has a Patch:||no||Platform:||All|
Recently, something has probably changed in the internal network of my standard e-mail provider, which causes both Beam and MDR to no longer be able to send e-mails via that provider's SMTP server (mail.hirschkaefer.de).
Inspection with Wireshark shows that as soon as the mail client sends e-mail data (via the DATA command), Haiku's TCP protocol implementation sends out three segments of 1448 bytes, filling the TCP window. After that, the connections is idle for a moment, then Haiku proceeds to retransmit the first of these segments several times. From that state, the connection never recovers (Haiku keeps trying retransmits without any success), finally causing the server to close the connection.
The TCP implementation of Linux does not seem to have any problem to talk to the same SMTP server.
Upon request, I can provide username and password to connect to the SMTP server for debugging purposes.