#554 5.4.6 Hop count exceeded - possible mail loop ##

[CAWJames]

Afternoon all,

 

We run in a coexistence hybrid, single 2010, single 2013 server and O365

 

All works very well, but occasionally we get the error in the title, for internal mail.

 

Any insight into this? I can't see any problems, apart from the system just juggling the email between servers!

 

Thanks

 

James

[mukz]

Do you have anything in the middle by any chance??

[CAWJames]

Nope, flow is O365 FOPE to Ex2013 and then on via connectors to Ex2010

[pantscat]

Do you have any mailboxes in O365? or just using FOPE?

 

Also - so your flow is from O365 via your on-premise Ex2010 box? Is that right?

Edited August 2, 2016 by pantscat

[CAWJames]

Yes, we have student accounts in O365, but all our staff accounts are on prem. This seems to affect those mailboxes on the Ex2010 server. So I suppose the solution is move everyone to 2013 and decommission the 2010!

 

Flow is from FOPE to the 2013 box and then on to the 2010 via the connectors

 

Thanks

 

James

[pantscat]

Usually when I've seen these types of errors it's to do with a config issue on the connectors - this might help: https://support.office.com/en-gb/article/Fix-email-delivery-issues-for-error-code-5-4-6-through-5-4-20-in-Office-365-81212ae4-4c36-4e8f-9546-e58b70cfd74b?ui=en-US&rs=en-GB&ad=GB