Anytime There Are Changes to the Aliases for Your Linked Gmail Mailbox(es), You Must Refresh the Aliases in Your Apollo Mailboxes Settings
When you link a mailbox in your Apollo App, you're connecting the primary email address you used to create that email account in Google (like firstname.lastname@example.org), and we'll pull in any aliases that are setup in your gmail account (other emails you own like email@example.com or firstname.lastname@example.org) so you can also use them as "send from" addresses in Apollo.
Apollo automatically syncs with your linked mailbox(es) every 10 minutes to ensure all relevant emails to and from your Apollo Contacts are saved in our database, however this auto-sync never applies to alias updates. Therefore, whenever you add, remove, or change any aliases for your linked email address (in your Gmail account), you must manually refresh the aliases in your Apollo mailboxes settings so that our system stays inline with your current gmail setup.
You can do this by going to Settings > You > Mailboxes, then clicking the three dots to the far right of each mailbox and selecting Refresh Send From Aliases:
You'll then receive a success message letting you know that they've been updated:
Important: Currently, Apollo only supports alias syncing for Gmail. Please contact email@example.com if you'd like to request that we support it for Microsoft Outlook mailboxes as well.