<form>
HTML element · 9 supported, 2 partial, 4 unsupported across 15 clients
Client Support
| Client | Category | Engine | Support |
|---|---|---|---|
| Gmail | webmail | Gmail Web | Supported |
| Gmail Android | mobile | Gmail Mobile | Supported |
| Gmail iOS | mobile | Gmail Mobile | Partial |
| Outlook 365 | webmail | Outlook Web | Partial |
| Outlook (New) | desktop | Outlook Web | Unsupported |
| Outlook Classic | desktop | Microsoft Word | Unsupported |
| Outlook iOS | mobile | Outlook Mobile | Supported |
| Outlook Android | mobile | Outlook Mobile | Supported |
| Apple Mail | desktop | WebKit | Supported |
| Apple Mail iOS | mobile | WebKit | Supported |
| Yahoo Mail | webmail | Yahoo | Supported |
| Samsung Mail | mobile | Samsung | Supported |
| Thunderbird | desktop | Gecko | Supported |
| HEY Mail | webmail | WebKit | Unsupported |
| Superhuman | desktop | Blink | Unsupported |
Client-by-client behaviour for <form>
Fully supports <form> (9): Gmail, Gmail Android, Outlook iOS, Outlook Android, Apple Mail, Apple Mail iOS, Yahoo Mail, Samsung Mail, Thunderbird.
Partial support (2): Gmail iOS, Outlook 365. Expect rendering quirks unique to each engine — partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.
No support (4): Outlook (New), Outlook Classic, HEY Mail, Superhuman. Plan fallbacks for these clients before relying on <form> in production sends.
Fixes & Workarounds
Outlook (New)
UnsupportedUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
Outlook Classic
UnsupportedUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
HEY Mail
UnsupportedUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
Superhuman
UnsupportedUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
Gmail iOS
PartialUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
Outlook 365
PartialUse links to a web form instead of embedding forms in email.
Before
<form action="/subscribe" method="POST">
<input type="email" placeholder="Email" />
<button type="submit">Subscribe</button>
</form>After
<table role="presentation" cellpadding="0" cellspacing="0">
<tr>
<td style="background-color: #6d28d9; border-radius: 6px;
padding: 12px 32px;">
<a href="https://example.com/subscribe"
style="color: #fff; text-decoration: none;
font-family: Arial, sans-serif;
font-weight: bold;">
Subscribe Now
</a>
</td>
</tr>
</table>Replace embedded form with a link to a hosted form
Production guidance for <form>
<form> is a HTML element. Across the email client matrix, 9 of 15 tracked clients support it fully, 2 only partially, and 4 not at all. The clients most likely to require a workaround for this feature are Outlook (New), Outlook Classic, HEY Mail. Each of them needs a tailored fallback — see the per-client examples above for the specific code fix Emailens recommends.
When in doubt, ship a baseline that renders without <form> and treat it as progressive enhancement on clients where support is verified. Emailens automatically detects cross-client divergence on this feature when you preview an email, so you can see exactly which template paths break before a campaign goes out.
Related Features
Test your email across all 15 clients
Preview rendering, catch CSS issues, and get actionable fixes — free.
Try Emailens FreeSupport data last updated Apr 27, 2026 · synced from caniemail.com via @emailens/engine.