The current message size limit is 20 MiB (20971520 bytes or ~ 20.97 MB). If the message (an attachment plus the text itself) exceeds this limit, the email will be bounced back with an error.
Emails with the attachments listed below are
automatically blocked by the Free Email Forwarding spam filter as they are rejected at the DKIM verification level. Such
emails will not be forwarded to the email address that is set as Forwarded to:
.bat, .btm, .cmd, .com, .cpl, .dll, .docm, .exe, .gz, .js, .lnk, .msi, .pif, .prf, .rar, .reg, .scr, .tar, .tar.gz, .tgz, .url, .vbs, .xlsm and .zip.