Which Android email apps support HTML signatures?
Support varies a lot by app. Here's the breakdown by what each one actually accepts:
Full HTML support (accepts pasted HTML, including images):
Spark Mail — Full support for htmlsig signatures, including logos and images. See install steps.
Aqua Mail — Supports full HTML signatures once you enable "Add text formatting" in the signature settings.
Rich-text support only (accepts a pasted rendered signature, not raw HTML code):
Outlook for Android — Won't accept pasted HTML source code, but does preserve formatting like fonts, colors, and links when you copy a rendered signature and paste it in. Images and logos typically won't display reliably. See install steps.
BlueMail — Supports basic rich text (bold, italic, underline) and still images, but not full HTML layouts.
Plain text only:
Gmail for Android — The Gmail app's signature setting is completely separate from your desktop Gmail signature and only supports plain text — no images, links formatting, or HTML.
Not sure which app you're using? If your signature isn't displaying correctly after installing it, check which category your app falls into above — a signature with logos or complex layout will only display fully correctly in Spark Mail or Aqua Mail.