If you've imported send-as addresses from Gmail, you can send your sequence from any of your email aliases.
How to use aliases with Sequences
Using an alias works best with single-stage sequences or with sequences where all stages should be sent regardless of whether the recipient opens or replies.
Aliases should not be used with sequences that require response tracking.
If you'd like to use a different email address to send a sequence that requires response tracking, we recommend using Delegated Sending.
To send a sequence using an alias, select a send as address in the From field within any (or all) stages:
When you send yourself a test message, it will always be sent from your primary email address (not an alias) to ensure it appears in your inbox for review.
Sending an email using an alias with Outlook is not currently supported by Mixmax.