Mel said:
OE6 allows you to automatically split into smaller messages. Do'nt know if
Outlook does or not.
However, some anti-spam filters will blocked multi-part e-mails (sent as
separate messages, not MIME multipart within the same message). That is
because an old trick is to slice up an infected e-mail across multiple
separate messages hoping there isn't enough content for the anti-virus
program to detect a pest. E-mail should never be sent as multipart
separate messages. There is no guaranteed delivery for e-mail so one of
the parts may not show up in the recipient's mailbox. E-mail does
provide some recovery and the parts might be delivered minutes, hours,
or many hours later and the recipient won't have all of them when they
expect to patch them back together.