Here’s a quick little post for you on this fantastic, turkey and football-filled Thanksgiving evening!
We first noticed the issue in WFFM 8.0 Update-2 (rev.150224) when adding an E-mail field to a form, but as of Update-4 (rev.150625), it’s still an issue.
With this configuration, the e-mail field will fail client-side validation if capital letters are used.
The proper regex string is stored in the /sitecore/system/Modules/Web Forms for Marketers/Settings/Validation/E-mail item, but a bug in the module doesn’t inject it properly.
This is a known issue and Sitecore Support has a patch to correct it. However, in the absence of the support patch, you can also chose to make it a Single-Line Text field and, in the Validation section, select Email Address.
This will inject the proper regex value.
Now, back to your regularly scheduled Thanksgiving activities!
Happy Sitecore trails, my friends!