Different Gmail signature for each alias: step by step

Gmail lets every "Send mail as" address keep its own signature. Open Settings, pick the address in the drop-down above the signature box, write the signature for that address, and save. Add the alias first if it is not listed yet.

Add the alias before you set its signature

A Gmail alias appears in Gmail as a "Send mail as" address. If your alias is not in the list, add it:

1. Click the gear icon, then See all settings.
2. Open the Accounts and Import tab.
3. In the Send mail as section, click Add another email address.
4. Enter your name and the address you want to send from, then click Next Step.
5. Click Send verification.
6. Open the confirmation message Gmail sends to that address and click the link in it.

If the address belongs to a school or work account, Gmail also asks for that server's SMTP details. Google's help page lists these steps in the same order.

Set a different signature for each address

1. Click the gear icon, then See all settings.
2. Find the Signature section on the Settings page.
3. Open the drop-down menu above the signature text box and choose the address.
4. Paste or type the signature for that address.
5. Repeat steps 3 and 4 for every address you send from.
6. Scroll to the bottom of the Settings page and click Save Changes.

Google's help says you can add a different signature for each address. The drop-down is how you tell Gmail which address a signature belongs to.

Troubleshooting

There is no drop-down above the signature box. Google's help says to check the Accounts and Import page and confirm your addresses appear under Send mail as. If the address is missing there, go back to the steps above.

The alias is listed, but the wrong signature appears. Open the Settings page again and check which address the drop-down shows for each signature. Then send a test from that alias to a second address you own and look at the received message. Google's help does not say what happens to the signature when you change the From address on a reply, so test it rather than assume.

The Gmail app on your phone shows one signature for everything. The Android steps for the Gmail app's mobile signature ask you to choose a Google Account, not an alias. The mobile signature is text only. Read how the Gmail app mobile signature works before you rely on it for an alias.

Google Workspace admins. Each alias has its own signature in the Gmail API. An admin tool or script has to write each one, not just the primary address.

How Sendoff handles this

Sendoff's Gmail deploy writes the signature to each "Send mail as" address it finds for the user, using the Gmail API's sendAs settings. If an address is no longer listed in Gmail, the deploy stops and tells you to sync the directory, then deploy again. You do not have to type the same signature into each alias by hand. Sendoff only sets the web signature in Gmail; it does not change the mobile signature in the Gmail app.

To create the signature itself, use the email signature generator. For team deployment to Gmail, see the Google Workspace integration.

Sources

• Google Help, "Create a Gmail signature": https://support.google.com/mail/answer/8395
• Google Help, "Send email from a different address": https://support.google.com/mail/answer/22370
• Google for Developers, "Alias and signature settings" (Gmail API): https://developers.google.com/workspace/gmail/api/guides/alias_and_signature_settings