Email clients consider email forms to be a security risk. While some email clients simply warn you of potential danger, others outright disable the forms. So if anyone wants to send out a form, they should know that most of their recipients will never be able to use it. And for those who can, they’ll think twice about submitting data when they see a warning from their email client.


External data submission

Upon submitting a form in many webmail clients, a JavaScript alert announces that the form is submitting data to an external page and asks if you want to continue:


1. Chrome




 

2. Firefox



 

3. Safari



 

4. Internet Explorer



 


Overview of form support in email


Email Client

Form is displayed

Form is functional

.Mac 

Yes

No

Yahoo! Mail

Yes

Yes

Yahoo! Mail Classic

Yes

No

AOL Webmail

Yes

No

Gmail 

Yes

Yes

Outlook.com

Yes

No

Apple Mail

Yes

Yes

Thunderbird

Yes

Yes

Penelope (Eudora 8)

Yes

Yes

Outlook 2007

No

No

Outlook 2003

Yes

No

Outlook Express 

Yes

Yes

Windows Live Mail

Yes

Yes

Lotus Notes 8 

Yes

Yes

Entourage

Yes

Yes


Source: css-tricks.com



Conclusion

By this uneven support for forms in emails, it's recommended to link to a form on a website rather than embedding it in the email. This is the safest, most reliable solution to pairing an email message with a form. More people will see it and be able to use it, and as a result participation will increase.