When your email sender stops sending in MCA Pilot, or AI Processing stops reading funder replies, use this guide to restore the connection and confirm everything is working. The most common causes are a changed mailbox password, an expired authentication token, or a disabled SMTP setting.

Gmail and Google Workspace

If you see Invalid login: Username and Password not accepted or Application-specific password required, your Google app password was revoked.

Changing your Gmail password automatically deletes all Google app passwords. MCA Pilot was using an app password to send on your behalf, so it no longer works.

Generate a new Google app password

Go to Google App Passwords and sign in.
Name the password MCA Pilot and click Create.
Copy the 16-character password without any extra spaces.

You must have 2-Step Verification enabled to create app passwords. If it is not enabled, turn it on first at Google 2-Step Verification.

Update the sender in MCA Pilot

In MCA Pilot, click your profile in the top right and select View profile.
Open the Senders tab.
Hover over the broken sender and click Update Password.
Paste the new 16-character app password and click Save.

Re-enable AI Processing for funder replies

If AI Processing was turned off, re-enable it so replies resume:

On the Senders tab, hover over the sender and click Edit.
Check the box labeled AI Processing, then click Confirm to save.
Check the IMAP Status field for updates. If the status updates, the connection is restored and replies will resume processing.

AI Processing runs every 5 minutes. During a large backlog, Google may temporarily throttle IMAP connections. If replies do not appear immediately, wait a few minutes and check the IMAP Status field again.

Test the connection

Still on the Senders tab, hover over the same sender and click Test Connection.
Enter an email address you can check and send the test.
If the sender status shows Verified with a timestamp, the connection is restored.

Microsoft 365 and Outlook

Microsoft 365 senders can disconnect when authentication expires. The fix depends on how the sender was originally connected.

Re-authenticate a Microsoft OAuth sender

If your sender was set up with Microsoft OAuth:

In MCA Pilot, click your profile in the top right and select View profile.
Open the Senders tab.
Find the Microsoft sender and click Sign in with Microsoft.
Select the email account and complete the sign-in.

Microsoft 365 Custom SMTP: 535 error

If your sender uses Custom SMTP and you see a 535 error, the issue is usually that SMTP AUTH is disabled in your tenant settings, not a password change. See Why am I getting an 'Invalid login: 535' error with Microsoft 365? to enable it.

IMAP password update note

If you also use the same mailbox to auto-process funder responses, update the IMAP password in the same sender record. On the Senders tab, hover over the sender and click Update password, then paste the new password into both the SMTP and IMAP fields. You must update both together; you cannot update one without the other. For full IMAP setup details, see Configure Your IMAP Settings.

Check for duplicate or stale senders

If you recently reconnected a sender after a password change but submissions are still failing or going out from the wrong mailbox, check whether duplicate or stale sender records still exist in your profile. Each sender has an Internal name field that defaults to the email address. If you have multiple senders with the same email—for example, a Google Workspace and a SendGrid connection for the same address—set a distinct internal name on each one so you can tell them apart, such as Deals (Gmail) and Deals (SendGrid).

In MCA Pilot, click your profile in the top right and select View profile.
Open the Senders tab and look for multiple entries with the same email address.
Switch to the Details tab, expand the Defaults section, and check the Default submission sender dropdown. Make sure it points to the sender you just reconnected.
Return to the Senders tab, hover over each sender with that email, and click Test Connection. Only the sender showing Verified with a recent timestamp is active.