Exchange error #5.7.17

[people3]

HI All,

We are having a strange problem when 1 customer try's to send us emails.

When they reply to one of our emails they receive a bounce back

#5.5.0 smtp;550 sorry, no mailbox here by that name. (#5.7.17)>

If they add other recipients they receive the email fine but ours still fail.

If they manually type in the email address it works.

This is only happening with this one customer and ours is the only failure they get.

If they send an email to an address that defiantly does not exist they get an error

#5.5.0 smtp;550 Invalid Recipient>

Our MX records are all correct and our customer is also using exchange 2003.

Any Ideas?

 

[58sniper]

Something in the middle? Anyone using a cloud based or appliance based filtering solution?

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[people3]

we use mimecast

I have spoke to them but they say there logs show no errors.

 

[davidari]

We are experiencing this same issue with someone outside our organization replying to our emails. SOmetimes they go through and other times he receives this error:

There was a SMTP communication problem with the recipient’s email server. Please contact your system administrator.
<EX-021.mail.navisite.com #5.5.0 smtp;550 sorry, no mailbox here by
that name. (#5.7.17)>

Have you reached any resolution on this?

Thanks!
-David

 

[people3]

HI David

We never got to the bottom of this - the error just went away.

Sounds simple but have you done a reboot?

I thought that it may be our Anti virus (we use Kaspersky)

But we never found out

Sorry i am unable to help

 

[davidari]

I have rebooted numerous times since this started occuring. We are running Symantec Endpoint - latest revision. It's always something.

Thanks!

-david

 

[people3]

do your MX records point straight to your exchange? or do you use any 3rd parties?

also do you know the setup of the company sending mail to you?