Can't Create Tickets via Email

[zotrs]

All of a sudden tickets created by emailing itsupport@domain.com stopped creating tickets.

Nov 24 14:39:33 otrs postfix/smtp[26726]: BCBD81816CA: to=<itsupport@otrs.domain.com>, relay=cf-04-3-2.domain.net[10.7.188.5]:25, delay=0.23, delays=0.09/0.08/0.05/0, dsn=5.4.6, status=bounced (host cf-04-3-2.domain.net[10.7.188.5] said: 554 5.4.6 Hop count exceeded - possible mail loop (in reply to end of DATA command))

[jojo]

this seems to be a mailrouting isse. not an OTRS issue