Why email being bounced back from other ISP because file size is too large?

[willy85]

Dear all Zimbra Forum members,

First of all I would like to thank you for your kind replies in my previous threads. Currently I'm still struggling my way to learn zimbra and other system in my workplace.

And just a few moments ago, an user of mine had reported a case that there's a person from other country tried to sent email to him but it was bounced back with a message that the recipient domain rejected the email because the file is too large.

AFAIK, I or the previous admin never put up rules that limits email size from the other domains. Can anybody help me with this problem? Does anyone know how to check the zimbra server mail size limit setting? Please let me know. Thank you for your kind reply.

Cheers,


Will85

[uxbod]

http://wiki.zimbra.com/index.php?tit...maxmessagesize

[willy85]

@uxbod:
Thanks for your reply, but isn't maxmessagesize parameters only affecting the email transaction that uses the SMTP from the Zimbra server (outgoing messages)? Or is it also affecting the messages that sent from the other ISP to mail server that uses Zimbra?

[uxbod]

I believe it is bi-directional as it affects

message_size_limit (default: 10240000)

The maximal size in bytes of a message, including envelope information.

Note: be careful when making changes. Excessively small values will result in the loss of non-delivery notifications, when a bounce message size exceeds the local or remote MTA's message size limit.

[willy85]

@uxbod
Ok, if that's the case. Thanks for your answer

Is there any email notification to the sender regarding that email is bounced back because of the size? If there is such an option, how can I set it up?

Because the case now is that there are many emails from other domains with size more than 10MB. Do you think I should raise the limiter? If I raise the limiter, in what way it will affecting my server?

[willy85]

Uh... Hello? Anyone?

Please help... Does anyone here can give me some inputs, if I raise the limit to more than 10MB (e.q: 15MB) does it secure? In what way it will affecting the email server?

Thank you

[uxbod]

10MB for a email is pretty big Are you sure they are valid and not bogus SPAM messages. You could modify the NDR that gets sent back to the sender to point them to your AUP (Acceptable Usage Policy) to state the reasons for bounces; one being maximum size of messages that will be delivered ?

[Jbrabander]

Oh 10MB isn't so large if you're talking about things like CAD drawings.

[uxbod]

Agreed, but there are more effective ways of transferring that type of file which has less impact on all your users by bogging down the mail system with them Could the user not try compressing the file aswell ?

[Jbrabander]

Agreed, but there are more effective ways of transferring that type of file which has less impact on all your users by bogging down the mail system with them

Smarty-pants.

Anyway, would FTP be available for transferring of your files?