Cisco Support Community
Community Member

is ironport blocking emails with large attachements?

I have recently adjusted my exchange server to accept attachments as large as 25mb but still when I tried to send an email with an attachment of 15mb it still bounce back as 552 552 #5.3.4 message size exceeds limit (state 18).

I was wondering if need to adjust anything on my Ironport to make sure it allows those large emails. If so, I hope somebody could help out on how to do this adjustment.



Community Member

Re: is ironport blocking emails with large attachements?

Ironport + Msoft quote figures around 135% inflation for MIME encoding on email.

(This doesnt account here 15*1.37=20.55)

If mail is outbound you might allow bigger size on your outbound Ironport default policy/or individual policy and retain the 25mb on the Inbound. Your Ironport cfg should be in line with the internal exchange limits

You shouldn't expect to get mail bang on 24.99mb


Community Member

is ironport blocking emails with large attachements?

I sort out the issue..

In microsoft exchange everything is configured well, to send and receive upto 25 MB. Usermail box permission also set for sending 25 MB attachment.  Evenif I can receive 15 MB attachment, it resulting in error while sending.

This was the error:- #550 5.3.4 SMTPSEND.OverAdvertisedSize; message size exceeds fixed maximum size ##

This message is generated by HUB-CASH server

No clue that email is screening by ironport.


Increase the message size limit in ironport

Mail Policies-> Mail Flow Polices -> Relay -> Max Message Size ->25 M

This relay is used for outgoing emails. (Note that the title for that page is confusing: Mail Flow Policy: RELAY - IncomingMail)

Community Member

This worked for me.  Thanks!

This worked for me.  Thanks!

Community Member

Thanks Buddy,

Thanks Buddy,

It worked for Me....

CreatePlease to create content