FortiMail VM Email Loop when sending

[David_Franzen]

Dear all,

I have a problem with a FortiMail  VM. I use my Fortimail as a gateway. Unfortunately, I have a loop when sending emails, which I cannot solve.

The following error scenario:

When I send an email from my M365 mailbox to another M365 mailbox this email goes into a loop and rejected with this error: "Remote server returned '554 5.4.6 < #5.4.6 SMTP; 554 5.4.6 Too many hops>'". When sending from my M365 to email addresses outside the Microsoft Cloud, the sending is successful.

Can you help me to solve this problem? I suspect the problem is because the 365 accounts are all accessible via the same IPv4 address?

Thank you very much for your help.

David

[Anthony_E]

Hello David,

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Thanks,

[Anthony_E]

Hello David,

We are still looking for someone to help you.

We will come back to you ASAP.

Regards,

[srajeswaran · Accepted solution]

I think you are hitting this issue - https://learn.microsoft.com/en-us/exchange/troubleshoot/mailflow/hop-count-exceeded-possible-mail-lo...

Can you apply the fix on the mail servers and check.

[David_Franzen]

Hello, I was able to detect a misconfiguration of a rule. The problem has been solved.

Thank you for your help.

[sahmed]

@David_Franzen , how did you resolve the issue? Can you please elaborate?

[MCORLOU]

Hello i'm facing the same problem with O365, there is a mail loop between our tenant and the recipient tenant.

The design is like this :
EXO ---> Fortimail ---> Web 
when i send an email to a recipient in another tenant 365 it's seems to do this :

EXO ----> Foritmail ----> EXO ----> fortimail ----> and again and again

Notice that we don't have problem with all the others domains. Do you have any solution to fix this problem ? the solution mark as solved in this thread can be applied in our context.