message vs attachment size

Scott Silva ssilva at
Thu Mar 9 20:14:00 GMT 2006

Kevin Miller spake the following on 3/9/2006 7:59 AM:
> Julian Field wrote:
>> It's very simple, the message size is the size of the file containing
>> the body of the text, for MTA's that have 2 files per message
>> (sendmail and Exim). For MTA's that have 1 file per message (Postfix
>> and ZMailer) it is simply the size of the file representing the
>> entire message including headers and envelope data.
>> Yes, I know that makes the figure slightly different for different
>> MTA's with the same mesage. But people only ever use it as an
>> approximate figure, e.g. 10MB. No-one cares if it is 10MB + 100 bytes
>> or 10MB - 100 bytes.
> Just to elaborate a bit, it may also be worth noting that when an
> attachment is encoded there is about a 25% increase in filesize so if
> someone asks what your limit is and you say 10 MB, from a practical
> standpoint they may only be able to attach a 7.5 MB doc.  Of course,
> anybody sending 7.5 - 10 MB files should be fed to the sharks, but
> that's a different rant...
> ...Kevin
Our execs routinely send 25 to 30 MB files to and from lawyers. It is easier
on my paycheck to just let them do it, then to get them to learn something

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