[AusNOG] Current "Best Practice" WRT email size

[Ted Cooper]

On 26/11/15 12:10, Ross Wheeler wrote:
> Lots of places still seem to have a 10MB limit, some smaller, some
> greater, but generally still in the low-tens-of-megabytes range.

Most versions of Exchange default to somewhere around 10MB. If it is a
problem for an Exchange client, I bump it to 20MB but that really is
only in extreme situations as it doesn't usually solve problems long term.

Exim defaults to 50MB and that has never been hit in practice by any of
my servers. The bigger problem with this difference is with everyone
else rejecting large emails - user training gets rid of the issue far
better than bumping up the limit. We'll never get them limit lifted
everywhere, so route around the problem.

The 33% overhead for files over email is also a hard concept for people
to get. "I'm sending a 20MB file but it gets rejected!" (by the other
end). Much easier to divert them to more appropriate technologies
without even thinking of email, or have their email client configured to
offload large files to Dropbox/WebDAV/etc.