On 07/08/2020 11:25, Cyborg via Exim-users wrote: > 91 1.619741 X 83.246.80.144 SMTP 60 C: QUIT > 92 1.620504 83.246.80.144 X SMTP 102 S: 221 > {serverhostname} closing connection > 94 1.669586 X 83.246.80.144 TCP 60 2872 → 25 [FIN, > ACK] Seq=252 Ack=521 Win=4380 Len=0 > 95 1.669610 83.246.80.144 X TCP 54 25 → 2872 [ACK] > Seq=521 Ack=253 Win=64046 Len=0 > > As this is basically the correct procedure to close a connection, as the > client (X) sends a FIN,ACK and the server reacts with an ACK. But, the > clients mta or TCP/IP stack awaits something else (probably the FIN the > server would send, if it hadn't gotten the FIN,ACK itself).
I think you'll find that the server sent a FIN as part of frame #92. I'm not too surprised that an IOT stack would not be TCP-standards confirming, but I'm glad to hear that it was fixed in an update. Laura, if your scenario matches this then you have bad software on at least one end. I'd still like to see the logging, in full not just described in your words, from both systems. -- Cheers, Jeremy -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/