gap in Fastmail
Partial gap is partly supported in Fastmail.
Supports gap and column-gap for flexbox.
Works in 7 of 21 · partial in 9 · not supported in 5
Which clients
- Works
- Apple Mail, Apple Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, Superhuman
- Partial
- Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook (New), Outlook iOS, Outlook Android, Outlook for Mac, Fastmail
- Not supported
- Outlook Classic, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, AOL Mail
Your reader in Fastmail may not see gap the way you wrote it, even if it looks right where you tested it.
What to do instead in Fastmail
Use padding or margin on child elements instead of gap
<table role="presentation" cellpadding="0"
cellspacing="0" border="0">
<tr>
<td style="padding-right: 16px;">Item 1</td>
<td style="padding-right: 16px;">Item 2</td>
<td>Item 3</td>
</tr>
</table>Show the original
<div style="display: flex; gap: 16px;">
<div>Item 1</div>
<div>Item 2</div>
<div>Item 3</div>
</div>A free account opens all 21 clients and keeps your checks for 7 days. Create a free account →
What Fastmail does with gap
caniemail record, tested upstream 28 Dec 2022
- Partial. Supports gap and column-gap for flexbox. Supports gap for multi-column layout (i.e. in conjunction with CSS column-count property)
Your next question
- Does unit-vw work in Fastmail?
Works in 18 of 21 · not supported in 2 · 1 untested
- Does unit-vh work in Fastmail?
Works in 17 of 21 · partial in 1 · not supported in 2 · 1 untested
- Does mix-blend-mode work in Fastmail?
Works in 13 of 21 · partial in 2 · not supported in 6
- Does writing-mode work in Fastmail?
Works in 13 of 21 · partial in 2 · not supported in 6
- Does filter work in Fastmail?
Works in 7 of 21 · not supported in 14
- Does grid-template-columns work in Fastmail?
Works in 7 of 21 · partial in 1 · not supported in 13
Questions
- How many email clients support gap?
- It works in 7 of 21, partial in 9, not supported in 5.
- What do I use instead of gap in Fastmail?
- Use padding or margin on child elements instead of gap.
- Does gap work in Apple Mail?
- gap works in Apple Mail. Closest to Fastmail: Apple Mail, which agrees on 192 of the 235 features both are tested on.
To see what else in your email Fastmail does not support, paste the whole email.
No signup · Five clients free, Outlook Classic included · All 21 with an account
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caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 28 Dec 2022 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping