Send email with username encoded into URL link?

[criscokid]

Is it possible in vBulletin to send an email to registered users that includes a link to anywhere on a vBulletin site and automatically logs a user in at the same time?

Example: Expedia publish their newsletters to their website and then send out a small text email saying that their latest newsletter is available to read (excellent idea to cut down on the number of returned emails due to some members close to having reached their mailbox size limit). The link they provide has the username encoded in to the URL.

Why do I want to be able to do this? I also publish my newsletter to my website and send a text email to my registered users. Many of those users click on the link, read the newsletter then read some of the forum threads. The problem is that they're not logged in - from an admin's point of view it looks like those registered users haven't dropped by in some time but in reality they have.

Getting users to click the 'remember me' checkbox when they log in isn't a way to fix the problem... many of the members on my site don't have a PC at home so use an internet cafe or access the site from work where they maybe hotdesk - most internet cafes delete all cookies and temporary files then reboot the PC after a user's session has ended.