RECEIVED attachment max size

[JMB]

What is the largest size a received attachment can be? Google searches show people answering from 5 MB to 20 MB. When I sent something that was about 18.7 MB (19,200,200) it bounced with the error message:

(reading confirmation): 552 5.3.4 a message size of 20483 kilobytes exceeds the size limit of 20480 kilobytes computed for this transaction

[Hubrisnxs]

20 mb if you use an email program like windows mail, outlook our mac mail. 8 mb if you use the browser and webmail