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Reconnect your email sender

V
Written by Victor Fteha

When a sender stops sending, a submission shows an error, or AI Processing stops reading funder replies, restore the existing sender instead of creating a new one. Match the error or symptom below, apply that fix, then confirm with Send test email.

If you have not added a sender yet, start with Connect Your Email to MCA Pilot.

Open the sender and read the error

Recovery starts on your profile Senders tab, not on a new sender form.

  1. Click your name or initials and select View profile.

  2. Open the Senders tab.

  3. Find the sender that failed and note the status or error text.

  4. After you apply a fix, hover the sender and click Send test email. A working sender shows Verified with a timestamp.

Prefer Update Password, Sign in with Microsoft, or Edit on the existing sender. Creating another sender for the same address is how duplicate records start.

Fix the matching problem

Open only the case that matches your error or symptom.

Gmail: Invalid login or Application-specific password required

Invalid login: Username and Password not accepted, Application-specific password required, and Invalid login: 534-5.7.9 Application-specific password required mean the Google app password MCA Pilot uses was revoked, never set, or replaced with a normal Gmail password.

Changing your Gmail password deletes every Google app password.

  1. Open Google App Passwords and sign in.

  2. If needed, turn on 2-Step Verification first.

  3. Name the password MCA Pilot, click Create, and copy the 16-character password with no extra spaces.

  4. In MCA Pilot, open View profile → Senders.

  5. Hover the broken sender and click Update Password.

  6. Paste the new app password and save.

  7. If the same mailbox also reads funder replies, paste the new password into both the SMTP and IMAP password fields. Update both together.

  8. Click Send test email and confirm the status shows Verified.

Full IMAP recovery steps: Configure Your IMAP Settings.

Gmail: Internal error

A Google Internal error on the sender is treated the same as an invalid or deleted app password.

  1. Create a new Google app password named MCA Pilot.

  2. Use Update Password on the sender and paste the new value.

  3. If AI Processing is enabled, paste the same value into both SMTP and IMAP password fields.

  4. Run Send test email and confirm Verified.

Wrong SSL/TLS or port for the provider

A sender can fail when Requires SSL/TLS, host, or port does not match the provider. Open the sender, click Edit, and set the values for your provider.

Provider

Host

Port

Requires SSL/TLS

Gmail / Google Workspace (SMTP)

smtp.gmail.com

465

Checked (TRUE)

Microsoft 365 business (Custom SMTP)

smtp.office365.com

587

Unchecked (FALSE)

Personal Outlook (Custom SMTP)

smtp-mail.outlook.com

587

Unchecked (FALSE)

SendGrid

smtp.sendgrid.net

587

Unchecked (FALSE)

For Gmail IMAP used with AI Processing, use host imap.gmail.com, port 993, and IMAP Requires SSL/TLS checked. For Outlook IMAP, use host outlook.office365.com, port 993, and SSL/TLS checked.

  1. Hover the sender and click Edit.

  2. Correct Host, Port, and Requires SSL/TLS.

  3. Save with Confirm.

  4. Run Send test email and confirm Verified.

Microsoft OAuth: sign-in expired

Microsoft senders connected with OAuth need a fresh sign-in when authentication expires.

  1. Open View profile → Senders.

  2. Find the Microsoft sender and click Sign in with Microsoft.

  3. Choose the email account and finish sign-in.

  4. Run Send test email and confirm Verified.

Microsoft 365 Custom SMTP: 535 authentication error

535 and 535 5.7.139 Authentication unsuccessful usually mean SMTP AUTH is disabled in the tenant or mailbox, not that the password rotated.

Enable SMTP AUTH with the steps in Why am I getting an 'Invalid login: 535' error with Microsoft 365?. That guide covers mailbox-level and tenant-level SMTP AUTH, GoDaddy-hosted Microsoft 365, and Azure AD Security Defaults.

Changes can take 5–10 minutes. Wait, then test the sender again from the Senders tab with Send test email or Test Connection.

SendGrid: DNS, domain auth, or bad credentials

SendGrid failures usually come from domain authentication, DNS, API key fields, or SSL/TLS mismatch on the sender.

  1. In SendGrid, confirm Domain Authentication shows Verified.

  2. Confirm DNS includes both SPF and DKIM for the sending domain. Copy each DNS record exactly into your DNS tool (for example GoDaddy, Squarespace, Cloudflare, or Namecheap) and recheck for typos or missing entries.

  3. In MCA Pilot, open the SendGrid sender and click Edit.

  4. Set Username to apikey (all lowercase).

  5. Set Password to the full current SendGrid API key.

  6. Set Host to smtp.sendgrid.net, Port to 587, and leave Requires SSL/TLS unchecked.

  7. Leave AI Processing unchecked on the SendGrid sender. Use your mailbox sender with IMAP when you want MCA Pilot to read funder replies.

  8. Save, then run Send test email or Test Connection.

For first-time SendGrid account and DNS setup, use How to Set Up A Sendgrid Account.

SendGrid: write ECONNRESET

write ECONNRESET means the SMTP server closed the connection unexpectedly. It is often transient during bulk sending.

  1. Wait 2–3 minutes.

  2. Resubmit the deal.

If the error continues after a successful test email, re-check the SendGrid sender fields and domain authentication above. See also Error from Sendgrid: write ECONNRESET.

No email accounts in the dropdown for a rep

An empty email-account dropdown during submit means the rep cannot use any sender yet. This is access configuration, not a broken SMTP password.

  1. Open the sender and click Edit.

  2. In Users, add the rep.

  3. Save with Confirm.

Also confirm the rep has a seat, can see the deal, and has Can submit deals. Full empty-dropdown troubleshooting: Troubleshoot sender access and an empty sender dropdown. Broader permissions checklist: How to Set Up Rep Access, Manager Visibility, and Sender Permissions.

Duplicate or stale senders for the same email

After a reconnect, submissions can still fail or leave from the wrong mailbox if older sender records remain.

  1. On Senders, look for multiple entries with the same email address.

  2. Give each one a distinct Internal name, such as Deals (Gmail) and Deals (SendGrid).

  3. On the Details tab, expand Defaults and set Default submission sender to the sender you just fixed.

  4. Run Send test email on each matching sender. Only the record that shows Verified with a recent timestamp is active.

If stale duplicates remain after that, contact support to remove them so only the active sender is left.

AI Processing stopped reading funder replies

Outbound sending and inbox reading are separate. If replies stopped, restore IMAP credentials and turn AI Processing back on.

  1. On Senders, hover the sender and click Edit.

  2. Check AI Processing and save with Confirm.

  3. If the mailbox password changed, click Update password and paste the new value into both the SMTP and IMAP password fields. Update both together.

  4. For Gmail, create a new Google app password if the account password changed, and approve any Google security or access alert about mail/IMAP access in the Gmail inbox.

  5. Check IMAP Status for updates. There is no separate self-serve IMAP connection test.

AI Processing runs every 5 minutes. During a large backlog, Google may temporarily throttle IMAP. Wait a few minutes and check IMAP Status again. Full IMAP setup: Configure Your IMAP Settings.

Confirm the sender works again

Do not resume live funder submissions until a test send succeeds.

  1. Hover the sender and click Send test email.

  2. Send the test to an address you own.

  3. Confirm the message arrived.

  4. Confirm the sender status shows Verified with a timestamp.

If the test still fails, re-read the provider error on the sender status and open the matching case above again. For first-time field values across providers, use Connect Your Email to MCA Pilot.

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