Some email clients will not accept exclamation marks at the end of the URL as being part of the URL, i.e., the clickable part of the URL does not contain the trailing exclamation marks.

Thunderbird will not accept any exclamation marks at the end of the URL. Gmail will refuse up to 2 exclamation marks: If there are 5 of them, the last 2 will be ignored. If there are 3, the last 2 will be ignored. If there is 1, it will be ignored.

The patch removes any exclamation marks from the end of URLs.