Troubleshoot errors when connecting an inbox with IMAP and SMTP

Last updated: November 27, 2024

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When you connect your inbox via IMAP and SMTP, you might receive an error during the connection process or in your email integration settings. To better understand why the error occurred, review the steps that take place in order to successfully connect your inbox via IMAP and SMTP:

HubSpot connects to the corresponding IMAP server on the given port.
HubSpot logs into the IMAP server with the email address and password that you entered, or the custom username if provided.
HubSpot connects to the corresponding SMTP server on the given port
HubSpot logs into the SMTP server with the email address and password that you entered, or the custom username if provided.
To verify the inbox is working, HubSpot sends a test email from your inbox to the BCC address for your account.

Understanding the process can help you better understand where the error occurred and how to resolve it. For example, if you see a SMTP Settings Incorrect error it means HubSpot could successfully connect and log into to the IMAP server, but encountered an error connecting to the SMTP server.

In the Table of Contents on the right, select an error message to learn about where the error occurred and how to resolve it.

IMAP settings incorrect

HubSpot cannot connect to the corresponding IMAP server on the given port.

Confirm the IMAP server and port is correct. Most IMAP ports will be 993 or 143.
Verify the server meets the technical requirements for connecting via IMAP and SMTP.
Your IT team might only allow certain IP addresses to connect with your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

IMAP authentication error

There was an authentication error with the IMAP server. However, the error messaging does not specify what caused the authentication error.

Confirm the IMAP server and port settings are correct. Most IMAP ports will be 993 or 143.
Review the steps for an UNAUTHORIZED error.
Work with your IT team or your email provider to see if they can provide additional visibility into these authentication errors. Some potential cases include:

Your IT team might only allow certain IP addresses to authenticate with your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.
Some servers return an authentication error when there are too many concurrent connections to a mailbox. Learn more about the concurrent connections HubSpot makes when you connect an inbox using IMAP.

IMAP validation error

HubSpot cannot validate the connection with the corresponding IMAP server on the given port.

Confirm the IMAP server and port settings are correct. Most IMAP ports will be 993 or 143.
Verify the IMAP server meets the technical requirements for connecting an inbox via IMAP and SMTP.
Your IT team might only allow certain IP addresses to access the IMAP service running on your IMAP server. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

SMTP settings incorrect

HubSpot was unable to connect to the corresponding SMTP server on the given port.

Confirm the SMTP server and port is correct. Most SMTP ports will be 465, 587 or 25.
Verify the IMAP server meets the technical requirements for connecting an inbox via IMAP and SMTP.
Your IT team might only allow certain IP addresses to connect with your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

SMTP authentication error

There was an authentication error with the SMTP server. However, the error message doesn't specify what caused the authentication error.

Confirm the SMTP server and port settings are correct. Most SMTP ports will be 465 or 587.
Review the steps for an UNAUTHORIZED error.
Your IT team might only allow certain IP addresses to authenticate with your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

Test email failed

There was an error when attempting to send a test email from your email server. Your IT team might only allow certain IP addresses to submit emails to your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

Unauthorized

There was an authentication error from your server indicating the credentials are incorrect. Unlike the other errors, this one can happen during either the IMAP or SMTP connection process.

Confirm the email and password are correct.
Some servers require a custom username to log in. Check with your IT team to see if your setup requires a custom username to connect.
Check to see if your server requires an app specific password.
Check your SSL certificate.
Your IT team might only allow certain IP addresses to authenticate with your inbox. If this is the case, your IT team will need to add the IP addresses HubSpot uses to connect your inbox to your allowlist.

Unauthorized - App password required for connection

Some email clients require users to create an app-specific password in order to login. Follow your email provider's steps to create an app-specific password, and use that app-specific password to log in.

Below are links to documentation on this issue for some commonly used providers:

Unauthorized - SSL Certificates not trusted

IMAP/SMTP servers are required to have SSL certificates signed by a trusted Certificate Authority. This error message indicates that you have an SSL certificate that is either malformed, outdated, or signed by an unrecognized authority.

To sign in and continue connecting your inbox, select the Allow non-secure certificate checkbox under the Advanced Options section when connecting your inbox via IMAP.

imap-server-security-checkbox

Because authentication methods, security settings, and available protocols can differ from one email server to another, it may be necessary to work with your IT team to troubleshoot these errors. If you experience any difficulty during the IMAP connection process, work with your IT team or administrator when you open a ticket with HubSpot Support, as your IT department can provide specific information needed to troubleshoot that HubSpot does not have access to.

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