Large messages are not accepted correctly

[foxcpp]

Discussed in #388

^{Originally posted by jpatters August 22, 2021}
I am having issues with attachments. The largest attachment I've gotten to go though successfully is 598KB. What size attachment should I be able to send/receive with the default configuration? I expected it would be 32MB based on the default value of max_message_size.
I am using S3 for message storage but I have also tried with fs storage and had the same result.

Thanks in advance.

[foxcpp]

I sent a 1.2 MiB message to maddy process and it got stuck in a loop with 100% CPU use.

[foxcpp]

Seems to be the regression introduced in 426c618, affecting 0.5.0.

[foxcpp]

Workaround for 0.5.0 is to set max_header_size to something larger than max_message_size:

smtp ... {
  ...
  max_header_size 33M
}