Instant Fax PortalSend/Receive Fax limit: 20Mb or 100 pages (whichever comes first).Email to FaxSend/Receive Fax limit: 10Mb or 100 pages (whichever comes first).Instant Fax ATAThere is no specific data size limitation, but it is recommended to break faxes up to 100 pages or less. Longer faxes have a higher potential to fail due to QoS.When end-users receive faxes with a file more than 10MB in size via Instant Fax ATA's Email, a link wherein you can download the file is sent instead as 10MB is the common maximum attachment size for email.