2.4.2 Automatic Splitting of Messages

All binary files larger than 300kB and smaller than 6 MB will automatically get split into smaller chunks of 300kB each and are sent as a MIME BASE64 attachment.

All TEXT and HTML files larger than 300kB and smaller than 6 MB will automatically get pk-zipped and are subsequently treated as binary files, subject to splitting and MIME encoding on delivery.

There also exists the possibility of uuencoding binary files using UUENCODE option upon request -See section 2.4.5 uuencoding Messages.