Use this guide when you cannot connect your mailbox to Sequences with SMTP/IMAP. It explains what information you need, how to prepare your mailbox, what common error messages mean, and what to check before contacting support.
SMTP/IMAP connections are available starting from Hunter’s Starter plan and let you send sequences from your own mailbox.
Before you start
To connect your mailbox through SMTP/IMAP, Hunter needs access to:
Your mailbox to send emails
Your outbox to detect replies
Your account activity to support open and link tracking
You will need to enter:
Email address
Password
Username (if your set-up requires it)
SMTP server details
Server address
Port
Encryption method: SSL or STARTTLS
IMAP server details
Server address
Port
Hunter may detect these details automatically. If it cannot, you will need to add them manually.
🔗 Learn more about how to connect your own domain using SMTP/IMAP
💡The server information can be found in the help centre of your email hosting service. Click the dropdown arrow below to:
View help articles about server information for the most common providers.
View help articles about server information for the most common providers.
Prepare your mailbox before connecting
Before you try to connect your mailbox in the Email Account Center inside Sequences, check the following:
Review your email provider’s SMTP/IMAP setup guide.
Make sure IMAP and SMTP access are enabled for your mailbox.
Check whether 2FA is enabled. - If your provider requires it, create and use an app-specific password instead of your regular password.
Confirm that your mailbox plan supports third-party email client connections.
Double-check that you entered the correct server names and ports.
Make sure you are using IMAP, not POP.
What to verify in your provider account
Some providers require extra setup before SMTP/IMAP works.
For example:
Ensure that IMAP and SMTP access are enabled, along with permission for third-party app access.
Zoho Mail may require IMAP/SMTP access to be enabled manually
Some providers only allow SMTP/IMAP on paid plans
Some providers block standard password login when 2FA is enabled
Common SMTP/IMAP connection errors
Below are the most common connection errors and what to check for each one.
SMTP authentication error
SMTP authentication error
👉 This usually means Hunter could not authenticate with your SMTP server.
Check these items:
Confirm the email address and password are correct.
Verify the SMTP server address, port, and encryption type.
Make sure you are connecting to the correct SMTP server for your provider.
Check whether 2FA is blocking the login.
Use an app-specific password if your provider supports or requires it.
IMAP authentication error
IMAP authentication error
👉 This means the IMAP login failed.
Check these items:
Confirm the email address and password are correct.
Verify the IMAP server address and port.
Make sure IMAP is enabled in your provider account.
Check whether 2FA is preventing the connection.
Use an app-specific password if needed.
Lack of sent mailbox
Lack of sent mailbox
👉 Hunter could not detect a Sent mailbox for this account.
What to do:
Confirm that your mailbox has a Sent folder.
Check whether the folder uses a custom name or special localization.
Contact support if the issue continues.
💡To connect your email account for sending in Hunter, it must have both an Inbox and a Sent folder. This means it needs to be a full email account with the ability to send and receive emails.
SMTP fatal error
SMTP fatal error
👉 A fatal error occurred while communicating with the SMTP server.
What to do:
Try the connection again.
Recheck the SMTP server details.
Confirm the provider allows SMTP connections from external apps.
Contact your provider if the issue continues.
IMAP no response error
IMAP no response error
👉 The IMAP server did not respond as expected.
What to do:
Try again.
Recheck the IMAP server address and port.
Confirm the provider supports IMAP access for your account.
Contact your provider if needed.
SSL error
SSL error
👉 This usually means there is a mismatch between the encryption settings used in Hunter and the server’s supported security settings.
What to do:
Verify whether your provider requires SSL or STARTTLS.
Confirm the port matches the encryption method.
Check that your mail server supports a recent SSL/TLS version.
Contact your provider if you are unsure which setting to use.
Timeout error
Timeout error
👉 This happens when the SMTP or IMAP server does not respond within the connection timeout window.
What to do:
Try again.
Confirm the server address is correct.
Check whether your provider is experiencing delays or service issues.
Contact your provider if the problem continues.
Connection refused
Connection refused
👉 The mail server rejected the connection attempt.
Possible causes include:
incorrect server or port
firewall or proxy restrictions
host-level blocking by the email provider
What to do:
Recheck the server settings.
Confirm your provider allows external SMTP/IMAP access.
Contact your provider if connections from third-party apps are restricted.
Host unreachable
Host unreachable
👉Hunter could not reach the server.
What to do:
Verify the server address carefully.
Check for typos in the hostname.
Confirm the server exists and is active.
Try again after verifying the provider documentation.
Unknown error
Unknown error
👉 This is a general error for issues that do not match a specific category.
What to do:
Recheck your credentials.
Recheck SMTP and IMAP settings.
Confirm IMAP/SMTP access is enabled.
Try again.
Contact support if the issue continues.
Provider and mailbox requirements
Not every mailbox can be connected through SMTP/IMAP in Hunter.
Keep these rules in mind:
Gmail, Google Workspace, and Outlook accounts should be connected to Hunter using the SSO options (“Sign in with Google” or “Sign in with Microsoft”), instead of configuring them via SMTP/IMAP.
Some providers, including Zoho Mail, may require a paid plan for SMTP/IMAP access.
Proton Mail addresses are not currently supported.
iCloud mailboxes are not recommended.
Your SMTP server must also support IMAP. Hunter requires access to a real mailbox that can receive and store email.
What to expect after a successful connection
When the connection works, your mailbox will be available in the Email Account Center inside Sequences for sending email sequences.
Hunter will then be able to:
Send emails from your connected mailbox
monitor replies
support open tracking
support link click tracking
When to contact support
Contact support if:
You confirmed all SMTP and IMAP details are correct
IMAP/SMTP access is enabled
You tested with the correct password or app-specific password
The connection still fails
The error remains unclear after checking this guide
When you contact support, include:
The email address you are trying to connect
The name of your email hosting provider
A screenshot of the SMTP and IMAP settings you entered
The exact error message shown in Hunter
💡 Support contact: contact@hunter.io or chat on the Hunter website