The current V4.01 Fix Pack is FP3.
Fix Pack 1
529 - 8bit Mime emails incorrectly decoded.
534 - Convert To HTML causes server crash.
536 - iPhone replies with attachments are corrupted.
Fix Pack 2
538 - Plain/text and plain/html attachments have incorrect boundary set.
544 - Server crash if additional crlf appended to MIME data.
Fix Pack 3
555 - Multiple text/plain from iPhones cause signature to be inserted into incorrect position.
See attachments section below.
Support for other platforms to follow shortly.