[msmtp-users] fetchmail with msmtp

[Neal Becker <ndbecker2@...20...>]

I'm using fetchmail with msmtp as mda:

poll host proto imap user me password ... mda "/usr/bin/msmtp -i -f %F
nbecker@...121..."

Problem is:

Aug 29 11:48:14 host=10.4.0.1 tls=off auth=off from=<>
recipients=nbecker@...121... smtpstatus=501 smtpmsg='501 <<>>:
missing or malformed local part' errormsg='envelope from address <> not
accepted by the server' exitcode=EX_DATAERR

These same messages just keep accumulating.  Every time fetchmail runs, it
tries again the same deliveries.  How do I teach it these are permanent
failures?