ida.org can't mail torproject.org ("Connection reset by peer")
A person at ida.org is trying to mail my torproject.org address, and the mail never arrives. I see these lines in our torproject.org mailserver (timestamps are in UTC):
Feb 21 10:58:30 eugeni/eugeni postfix/smtpd[17909]: connect from mail5.ida.org[129.246.225.242]
Feb 21 10:58:32 eugeni/eugeni postfix/smtpd[17909]: SSL_accept error from mail5.ida.org[129.246.225.242]: Connection reset by peer
Feb 21 10:58:32 eugeni/eugeni postfix/smtpd[17909]: lost connection after STARTTLS from mail5.ida.org[129.246.225.242]
Feb 21 10:58:32 eugeni/eugeni postfix/smtpd[17909]: disconnect from mail5.ida.org[129.246.225.242] ehlo=1 starttls=0/1 commands=1/2i.e. it is trying to connect to us, and then it's hanging up.
The issue repeats, e.g. mail5.ida.org comes back and tries again 60 minutes later, and the same "Connection reset by peer" issue stops it then too.
For comparison, mail from ida.org directly to moria.csail.mit.edu (e.g. my @freehaven.net address) does work (times in EST):
Feb 21 06:32:49 moria postfix/smtpd[64015]: connect from mail4.ida.org[129.246.225.241]
Feb 21 06:32:49 moria postfix/smtpd[64015]: setting up TLS connection from mail4.ida.org[129.246.225.241]
Feb 21 06:32:50 moria postfix/smtpd[64015]: Anonymous TLS connection established from mail4.ida.org[129.246.225.241]: TLSv1.2 with cipher RC4-SHA (112/128 bits)
Feb 21 06:32:50 moria postgrey[2193]: action=pass, reason=triplet found, client_name=mail4.ida.org, client_address=129.246.225.241, sender=xxx@ida.org, recipient=arma@freehaven.net
Feb 21 06:32:50 moria postfix/smtpd[64015]: 48FD91E03BE: client=mail4.ida.org[129.246.225.241]
Feb 21 06:32:50 moria postfix/cleanup[64106]: 48FD91E03BE: message-id=<8o7jf1knqetkgvld41v8dken.1582284768637@emailplus.mobileiron.com>
Feb 21 06:32:50 moria postfix/qmgr[2303]: 48FD91E03BE: from=<xxx@ida.org>, size=6337, nrcpt=1 (queue active)
Feb 21 06:32:51 moria postfix/local[64128]: 718821E030F: to=<arma@seul.org>, relay=local, delay=2.5, delays=0.19/0/0/2.3, dsn=2.0.0, status=sent (delivered to command: /usr/bin/procmail)
Feb 21 06:32:51 moria postfix/qmgr[2303]: 718821E030F: removed(moria's log mentions mail4, not mail5, but eugeni is seeing failures from both mail4 and mail5.)