I updated my .sig for my business email to include a faux-URL of tel://+1 718 xxx yyyy for my business phone. I didn't think too much of it...it's possible if you have a semi-aware client that you could click on it an initiate a call I guess, if the tel: method is registered.

Anyway, I did this and went on my merry way doing work.

I just found out that AOL scans incoming mail for a variety of things, I assume to deflect spam and phish mail. In this case I got my message to a colleague bounced because tel:// isn't a valid URL, specifically I got:

Remote host said: 554-: (HVU:NR) This email is rejected for containing one or more URLs which do not follow RFC guidelines. For additional inforFšpon, ID=7ba403506641df
554 TRANSACTION FAILED

Argh.

So, I removed the anchor tag...will see if AOL continues to bounce this or not. It seems really stupid that so much energy and processing power has to go into deflecting viruses, spam, phish, etc.