Set Up Your Business Email on Outlook, iPhone and Android (IMAP and SMTP)

You have a mailbox on your own domain. Now you want it on your laptop and your phone, with the same folders, the same sent items and no "cannot verify server identity" warnings. This guide walks through the settings that matter, how to enter them in Outlook, on iPhone and on Android, and how to fix the errors people hit most often.

One rule before we start: use the exact incoming and outgoing server names from your welcome email or from your support team. Do not guess them. A wrong host name is the most common cause of certificate warnings and failed logins.

The settings you need

Every mail app asks for the same handful of values. Collect them before you open the app.

Setting	Value	Notes
Account type	IMAP	Keeps mail on the server and syncs all devices
Incoming server	From your welcome email	Often a mail host name, not your website address
Incoming port	993	Encryption: SSL/TLS
Outgoing (SMTP) server	From your welcome email	Often the same host as incoming
Outgoing port	465 or 587	465 = SSL/TLS, 587 = STARTTLS
Username	Your full email address	Not just the part before the @
Password	Your mailbox password	Not your hosting control panel password
SMTP authentication	On, same as incoming	Required to send

IMAP or POP3?

Choose IMAP. With IMAP, the server holds the master copy of every message and folder. Read a message on your phone and it shows as read on your laptop. Delete it on the laptop and it disappears from the phone. POP3 downloads messages to one device and, depending on settings, removes them from the server. That works for a single computer, but with two or more devices it creates split inboxes and lost sent items. POP3 uses port 995 with SSL/TLS if you really need it.

465 or 587?

Both are encrypted submission ports. Port 465 starts TLS immediately (implicit TLS). Port 587 connects in plain text and then upgrades with STARTTLS before you log in. Use whichever your provider lists first. If one fails on a hotel or office network, try the other. Do not use port 25 for sending from a mail app: many internet providers block it for home connections, and it is meant for server-to-server delivery.

Test the server before you blame the app

If you are on a computer, you can check that the server answers and that its certificate matches the host name. Replace the host with the one from your welcome email.

# IMAP over SSL/TLS
openssl s_client -connect mail.example.com:993 -servername mail.example.com

# SMTP with implicit TLS
openssl s_client -connect mail.example.com:465 -servername mail.example.com

# SMTP with STARTTLS
openssl s_client -starttls smtp -connect mail.example.com:587 -servername mail.example.com

Look for Verify return code: 0 (ok) near the end of the output. A different code usually means the host name does not match the certificate, which is exactly what your phone will complain about. If the command hangs with no output, a firewall on your network is probably blocking that port.

Outlook on Windows and Mac

Outlook tries to detect settings automatically. Automatic detection works when your domain has the right autodiscover records. If it picks the wrong server or fails, set it up manually.

1. Open Outlook and go to Settings (or File in classic Outlook) and choose Add account.

2. Enter your full email address. In classic Outlook, open Advanced options and tick Let me set up my account manually. In the new Outlook, choose to add an IMAP account when asked for the provider.

3. Select IMAP.

4. Incoming: your server name, port 993, encryption SSL/TLS.

5. Outgoing: your SMTP server name, port 465 with SSL/TLS, or 587 with STARTTLS.

6. Enter your full email address as the username and your mailbox password, then finish.

After the first sync, check that Outlook uses the server's Sent and Trash folders. In classic Outlook this is under the account's IMAP settings. If Outlook creates its own "Sent Items" folder next to the server's "Sent" folder, your phone and laptop will show different sent mail.

iPhone and iPad (Apple Mail)

1. Open Settings, then Apps, then Mail, then Mail Accounts. On older iOS versions the path is Settings > Mail > Accounts.

2. Tap Add Account, then Other, then Add Mail Account.

3. Enter your name, full email address, password and a description. Tap Next.

4. Make sure IMAP is selected at the top.

5. Under Incoming Mail Server, enter the host name, your full email address as the user name, and your password.

6. Under Outgoing Mail Server, enter the SMTP host, your full email address and the same password. iOS marks these as optional, but most servers require them to send.

7. Tap Next. iOS tries SSL first and picks the ports on its own.

If sending fails, open the account, tap the outgoing server under SMTP, then the primary server. Check that Use SSL is on, authentication is Password, and the port is 465 or 587. Under Advanced for the incoming side, confirm Use SSL is on and the port is 993.

Android

Android phones ship with different mail apps. The Gmail app and Outlook for Android both handle IMAP accounts on any domain.

Gmail app

1. Open Gmail, tap your profile picture, then Add another account, then Other.

2. Enter your full email address and tap Manual setup.

3. Choose Personal (IMAP) and enter your password.

4. Incoming settings: server name, port 993, security type SSL/TLS.

5. Outgoing settings: tick Require sign-in, then server name, port 465 with SSL/TLS or 587 with STARTTLS.

6. Choose a sync frequency and finish.

Outlook for Android

Tap Add account, enter your address, and when Outlook asks for the provider choose IMAP. Turn on Advanced settings and fill in the same incoming and outgoing values as above.

Common errors and what they mean

• "Cannot verify server identity" or certificate warning: the host name you typed is not on the server's certificate. Use the exact host from your welcome email. Do not tap "Continue" or trust the certificate just to make the warning go away.

• "Authentication failed" or "Username or password incorrect": check that the username is the full email address. Reset the mailbox password from your control panel or webmail if needed. Several failed attempts in a row can trigger a temporary block on some servers, so wait a few minutes before you retry.

• Receiving works, sending fails: SMTP authentication is off, the outgoing password is empty, or the port is blocked on your network. Try the other submission port.

• "Relay access denied" (often code 554 or 550): the server does not know who you are. Turn on outgoing authentication.

• Sent mail missing on other devices: the app saves sent mail to a local folder. Map the Sent folder to the server's Sent folder.

• Messages disappear from the server: the account was added as POP3. Remove it and add it again as IMAP.

Before you finish

Log in to webmail once and confirm that a test message you sent from your phone appears in Sent. Send a test to an external address and check it does not land in spam. If it does, the cause is usually missing SPF, DKIM or DMARC records on your domain, not your phone settings. Your provider can confirm those records are in place.

Run your business email on IM HOST

IM HOST Email Hosting gives you mailboxes on your own domain with spam filtering and webmail, and it works with Outlook, Apple Mail and Android apps over standard IMAP and SMTP. If you need a domain first, you can register one on our Domains page. Moving from another provider? Our free migration covers email too. Engineers are available 24/7 to send you the right server settings and help you connect each device.