POP3 response not properly byte-stuffed

[Spunc]

Problem

When retrieving an e-mail via POP3 that has a termination octet within its content, the response from Greenmail is not byte-stuffed. As a consequence, proper working email clients may cut of the part of the email that follows after that point.

Affected version

I found the problem with Greenmail/standalone 1.6.9.

How to reproduce

1. Send an email to Greenmail which contains a termination octet within its content, e. g.

This line will be transferred.

.

This line will not be transferred.

2. Connect an email client (I used Thunderbird) via POP3 to the inbox at Greenmail. The client will only download the email until it sees the termination octet.

Background

RFC 1939 mentions at section 3:

If any line of the multi-line response
begins with the termination octet, the line is "byte-stuffed" by
pre-pending the termination octet to that line of the response.
Hence a multi-line response is terminated with the five octets
"CRLF.CRLF".

[marcelmay]

Thanks alot, @Spunc !

Just backported the fix to 1.6.x branch if you want to try out snapshot version. I plan to roll a 1.6.11 release this weekend.