We design a lot of emails over here at MB (A. LOT. OF. EMAILS.).  One of the biggest hurdles to overcome is buttons that work across all* email clients. Of course, there are plenty of other headaches to deal with (nested tables, inline styling, Outlook), but making bulletproof buttons is a good thing to have in your arsenal. Below is a link to a great article from Litmus that talks about a few possible approaches. We use “VML-Based” approach, as it seems the most stable and consistent. Go get ’em.

Bulletproof Buttons in Email

Most Used Email Clients

Related, check out this recent breakdown of the most used email clients. Maybe it’s about time we ignore all the complications with Outlook!