nrdvana
commented
5 years ago Nevermind. I just found documentation in Net::Cmd that:
- datasend ( DATA ) Send data to the remote server, converting LF to CRLF. Any line starting with a '.' will be prefixed with another '.'. DATA may be an array or a reference to an array. The DATA passed in must be encoded by the caller to octets of whatever encoding is required, e.g. by using the Encode module's encode() function.
so Email::Sender::SMTP is written correctly, and my problem must be elsewhere.
Hi, I recently upgraded my entire perl ecosystem to latest versions, and within a month ran into a new problem where something in the chain of Email::Sender::Transport::SMTP::Persistent is not performing SMTP "dot stuffing". Specifically, if one line of the DATA of an SMTP message begins with "..", the server will strip out the first character according to the SMTP protocol.
https://wordtothewise.com/2018/11/why-do-my-urls-have-two-dots/
We send millions of emails a month, but it is also extremely rare that any line of a message would begin with "..", and also unlikely that anyone would even notice, so I can't say whether this bug was caused by the version bump or if it has always been there. Someone noticed this one because a URL with a "key" in it just happened to contain ".." and it just happened to land on the line boundary when wrapped, resulting in a broken key.
Do you know offhand where in the code the dot stuffing would have been happening? Was it ever part of the module? Did it used to be handled by Net::SMTP?