Maximum letter size

The maximum size of a sent letter is 50 MB.

Important points:

  • The SMTP protocol does not support the transfer of binary data and for this it encodes all attached files using the Base64 algorithm, which increases the message size by 1.5-2 times.
  • Not all mail services are capable of accepting letters of this size (for example, in Gmail, the size of a letter should not exceed 25 MB).