#46 Email attachments bloat by ~1.5X compared to estimate

[Bill Thies]

The Server tries to estimate the size of the attachment
that it is sending to a given client, but currently the
final email ends up being from 1.2 to 1.5X bigger than
anticipated. This makes it hard to do a precise
estimate, which is important for some users that have a
strict cutoff on the size of attachments they can download.

Could the bloat be due to Base64 encoding? Ideally, we
would be able to precisely estimate the size of the
final attachment (without actually fully writing the
email.) We already use the zip classes in Java to see
how big given file entries would be.