Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

If I'm right Postfix counts mail size with an attachment sent to multiple receivers as one big e-mail.

Eg.: User sends mail with 8 MB attachment to two receivers. Postfix thinks it's 2 x 8 MB = 16 MB mail. And when message_size_limit is by default 10240000 bytes ~ 10 MB it rejects it.

My question is: Is there a way to tell Postfix to count the attachment only once? I'd like to avoid setting bigger message_size_limit.

share|improve this question

1 Answer 1

up vote 2 down vote accepted

Your assumption is not correct.

Postfix stores messages to multiple recipients in a single queue file, which is why you can see 250 2.0.0 Ok: queued as 99BF8300096. It does not increase the size for the file as a multiple to the number of recipients, though multiple recipients may cause (slightly) more envelope (header) information.

message_size_limit (default: 10240000 bytes)
    The maximal size of a Postfix queue file, including envelope information (sender, recipient, etc.).

Edit. This is pobably what you're mistaking:

[t]he actual length of MIME-compliant Base64-encoded binary data is usually about 137% of the original data length, though for very short messages the overhead can be a lot higher because of the overhead of the headers. Very roughly, the final size of Base64-encoded binary data is equal to 1.37 times the original data size + 814 bytes (for headers).
-- http://en.wikipedia.org/wiki/Base64#MIME

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.