Tutorial · Email hosting

Find your IMAP and SMTP settings for a custom domain

Checked against Email hosting's documentation on 27 October 2026

Why 4fleet needs this

4fleet reads enquiries from your mailbox over IMAP and sends quotes and confirmations over SMTP, so it signs in to both servers with the mailbox address and its password. When you enter the address, 4fleet looks up the domain and fills in the servers it finds. If it finds nothing, it fills in a guess (imap. and smtp. in front of your domain), and a wrong guess makes the connection fail.

4fleet accepts IMAP port 993 or 143, and SMTP port 465, 587, 25 or 2525.

Steps

Find out who hosts the mailbox. It is the company where you sign in to read that mail on the web, often your website host or domain registrar.
Open that host's help page for setting up a mail app, or its control panel. On home.pl, for example, the server details are in the Panel Klienta under Poczta: select opcje next to the mailbox, then Serwery pocztowe.
Write down the IMAP server name, its port and its security type (SSL/TLS or STARTTLS). OVHcloud's MX Plan, for example, lists imap.mail.ovh.net (or ssl0.ovh.net) on port 993 with SSL/TLS.
Write down the SMTP server name and port. OVHcloud lists smtp.mail.ovh.net (or ssl0.ovh.net) on port 465 with SSL/TLS.
Check what the host says to use as the username and password. OVHcloud, for example, uses the full email address and the password of that email account.
If the host's page says the address forwards mail to another mailbox and has no inbox of its own, stop here and use the mailbox it forwards to. Cloudflare Email Routing, for example, forwards incoming mail to destination addresses you verify, and does not give you an inbox to sign in to.

Finish in 4fleet

Open Settings > Communications > Email accounts and select Add email account.
Enter the address in Your work email address and select Continue, then enter the mailbox password.
Open Advanced settings and compare IMAP host, IMAP port, SMTP host and SMTP port with what you wrote down. Leave Use TLS on when the IMAP port is 993.
Select Connect. 4fleet signs in to both servers before it saves the mailbox.

If your domain's mail is hosted by Google, 4fleet asks for an app password instead (see the Google app password tutorial). If it is hosted by Microsoft 365, 4fleet shows Connect with Microsoft.

Official sources

The 4fleet side, step by step

Connect your business mailbox
Connect a business mailbox by IMAP and SMTP so 4fleet can read client emails and send quotes from your address.
Fix a mailbox that will not connect
Match the message in the Connect your mailbox window to its cause and fix a refused password, server, port or limit problem.

Frequently asked questions

4fleet says "This address only forwards mail". What now?

Your domain uses a forwarding service, such as ImprovMX, Cloudflare Email Routing, ForwardEmail, or the forwarding that Namecheap and Porkbun offer. Mail to that address is passed on to another mailbox, so there is nothing to sign in to. Connect the mailbox it forwards to instead, for example the Gmail or Outlook address that receives the copies.

4fleet says it could not reach my mail server, or that the certificate was not accepted

The server name or port in **Advanced settings** does not match your host. Check them against your host's page. A certificate error often means you entered your own domain as the server name while the host's certificate is issued for its server address. home.pl, for example, gives a server address such as serwer12345.home.pl and says you can use your domain name instead only if you have an SSL certificate for that domain.

The servers look right but the password is refused

Check that you are using the password of the mailbox itself, which may differ from the login to your host's control panel. If you can, sign in to the host's webmail with the same password to confirm it works.

Sending fails but receiving works

Check the SMTP port. 4fleet tests port 465 when it looks for your servers but does not test 587, so a host that only offers 587 shows up only when you select **Connect**. Use the SMTP port and security type from your host's page.