How do I set up a mailbox using IMAP on my device or mail client?


In August 2021, we announced that we are disabling legacy authentication on our mail servers and you should check your settings. This change does not mean you need to change your IMAP/SMTP server, only that you review the authentication method used.

Our standard and premium mailboxes can be configured on your device or through your preferred mail client using either IMAP or POP3.

We recommend using IMAP rather than POP3 because IMAP keeps your mailbox synchronized across multiple devices. For example, you can access the same mailbox from your phone, tablet and computer. If you delete or move an email on one device, the change will also be reflected on your other devices. 

Setting up your mailbox using IMAP 

The exact steps for adding a mailbox will vary depending on your device or mail client. The names of individual settings may also differ between applications.

When adding your mailbox, select IMAP as the account type and use the following settings:  

Username: Your full email address (i.e. [email protected])
Password: Your mailbox password 

Incoming mail – IMAP 

Incoming Server: imap.extendcp.co.uk
Incoming Port: 993 
Encryption/Security:  SSL/TLS 
Authentication: Password 

Outgoing mail – SMTP 

Outgoing Server: mta.extendcp.co.uk 
Outgoing Port: 587 
Encryption/Security:  STARTTLS 
Authentication: Password 

Alternatively, if STARTTLS is not available, you can try SSL/TLS alongside port 465. 

Your outgoing mail server should be configured to require authentication using the same full email address and mailbox password. 


Setting up your mailbox using POP3

If you prefer to use POP3, use the following settings:

Username: Your full email address (i.e. [email protected])
Password: Your mailbox password 

Incoming mail – POP3 

Incoming Server: pop3.extendcp.co.uk 
Incoming Port: 995 
Encryption/Security:  SSL/TLS 
Authentication: Password 

Outgoing mail – SMTP 

Outgoing Server: mta.extendcp.co.uk 
Outgoing Port: 587 
Encryption/Security:  STARTTLS 
Authentication: Password 


Which should I use: IMAP or POP3? 

We recommend IMAP for most users.

With IMAP, your mailbox remains synchronized between your devices. This means that actions such as reading, deleting or moving messages are reflected across your phone, tablet and computer.

POP3 instead downloads the messages to the device it's connected to directly from the mail server and is more suitable if you specifically want your email stored locally on one single device (they will not sync across multiple devices).

Our mail servers use password authentication. When configuring your account, enter your full email address as the username and your mailbox password as the password.

If you are unsure how to enter these settings, consult the documentation for your specific device or mail application, as the terminology and setup process can vary between products.



Article ID: 258
Created On: Fri, Mar 13, 2015 at 11:50 AM
Last Updated On: Fri, Sep 18, 2026 at 4:49 PM

Online URL: https://www.heartinternet.uk/support/article/how-do-i-set-up-a-mailbox-using-imap-on-my-device-or-mail-client.html