php - How to deal with long links in HTML-emails

Question

I've searched the web on this and I can find two solutions:

1. Use a URL-shortner.
2. Use brackets < > to allow insertion of whitespace. This only applies to plain-text emails.

I'm sending HTML emails that contains sensitive information, like password recovery links and auto-authentication links. These secure links are, by their nature, quite long. Easily longer than 70 characters or whatever arbitrary limit is imposed on e-mail bodies.

Obviously I can't use any form of URL-shortning because it would circumvent any secure cryptography technique I've used for the links.

I suppose the largest issue is that the links aren't wrapped nicely by email clients. The nice word-wrapping is supported in CSS3 technique, so there is no way MS Outlook will ever support this.

How do I make it so the links are not visually disruptive and possibly easy to copy-paste in case of email client malfunction?

Example

If the link doesn't seem to work, try copy-pasting it to your browser: hxxp://development/#auth/YoxOntz0Oj0ExOiJfcmFuG9tbmVzcyI7czoxOTI6kJsYkV0qMGMuZ1pFZVQ5YkRQNDZPR200Unl60dGlpNlhZZC9QcEVeH0lvV2NVVlpWWFcwWlF0VjRyc0p4akYzclJ0GTkJmSlgxco0aEtDS0FuTlBVSXAxUVhCcGdRNGpHMVl5UGZMRFVacDVSQ1BqcU0tKYlNxZ0FqYXpjTkNqTS9LV29xSk4ydGtyeFpNdV0c2VLMERUbEYwc08xUWU5aXR0GOXl0bVFpcjlXeGZjUE100S0o1L1FcmQ4MmhOdm5LUSI7fQ

Additional notes:

I do not want my links to expire. If I want them to expire at all I'd have a time frame of months, not hours. These links are not just password recovery links.

Answer 1

Have you tried the Microsoft proprietary word-break:break-all; ?

<td style=“word-break:break-all;”>

---

This worked best for me (best compatibility across vendors):

<p style="word-break:break-all;">
    <font style="word-break:break-all;">hxxp://really_long_link</font>
</p>

Tested on: MS Office 2007/2010, outlook.com, hotmail.com, gmail.com, yahoo.com (yahoo did not display nicely)

---

While this was edited to include <p>...</p> I would highly discourage the use of paragraph tags in HTML email if spacing is impotant since email clients interpret these differently.