does anyone know if there is a specific setting to adjust the maximum allowed mail size for the Check Point TED/emaild MTA, running on

Right now large mails, like i.e. 300mb after encoding (please don't ask why people do this) get [...]relay=[]:10025, delay=49, delays=30/0/0/19, dsn=4.0.0, status=deferred (host[] said: 451 Retry later. Email Session ID: {5ACC-[...], and never get accepted.
I haven't figured out the actual limit for the internal CP MTA. The receiving Check Point Postfix MTA on tcp/25 has no limits. TE/TX limits are like 15mb and fail open.

Cheers Chris