Set Up Business Email in Classic Outlook for Windows (IMAP, Manual Setup)

Classic Outlook, the desktop program that comes with Office and Microsoft 365, still runs on most office PCs and connects to an IMAP mailbox directly from the machine, with no cloud sync. Its add-account wizard tries to guess settings and often guesses wrong for a custom domain, so this guide uses the manual path, which shows every field. Afterwards there are two checks worth a minute: outgoing authentication and where Outlook stores Sent items.

Quick answer

File, Add Account, enter the address, open Advanced options, tick Let me set up my account manually, Connect, choose IMAP. Incoming mail.oqumail.com, port 993, encryption SSL/TLS. Outgoing mail.oqumail.com, port 587, encryption STARTTLS. Next, enter the webmail password, Connect. If the wizard will not accept it, add the account through Control Panel, Mail, instead.

The settings you will enter

• Incoming (IMAP) server: mail.oqumail.com, port 993, SSL/TLS on
• Outgoing (SMTP) server: mail.oqumail.com, port 587, STARTTLS (apps that offer only an SSL switch: on, with port 587)
• Username: your full email address, for both incoming and outgoing
• Password: the same password you use for OquMail webmail

Step by step

1. Open Outlook. Click File, then Add Account (under Account Information).
2. Type your full email address. Click Advanced options, tick Let me set up my account manually, then click Connect.
3. Choose IMAP from the account types.
4. Incoming mail: Server mail.oqumail.com, Port 993, Encryption method SSL/TLS. Leave Require logon using Secure Password authentication (proof that email really comes from your company) unticked.
5. Outgoing mail: Server mail.oqumail.com, Port 587, Encryption method STARTTLS. Click Next.
6. Enter your webmail password and click Connect. Outlook tests both servers and shows "Account successfully added". Untick Set up Outlook Mobile unless you want that, and click Done.
7. Check outgoing authentication: File, Account Settings, Account Settings, select the account, Change, More Settings, Outgoing Server tab. My outgoing server (SMTP) requires authentication must be ticked with Use same settings as my incoming mail server.
8. Send a test message to another address you own and reply from there.

If the wizard refuses the account

Some Outlook builds loop on the password screen for IMAP accounts. Close Outlook, open Control Panel, search for Mail, open Mail (Microsoft Outlook), click Email Accounts, New, choose Manual setup or additional server types, then POP or IMAP. The classic form appears with every field: your name, address, account type IMAP, the two servers, your full address as user name, the password. Click More Settings, set the ports and encryption on the Advanced tab (incoming 993 SSL/TLS, outgoing 587 STARTTLS), tick outgoing authentication on the Outgoing Server tab, then Test Account Settings.

Sent items and folders

Outlook IMAP accounts sometimes save Sent items into a local folder rather than the server's Sent folder, so webmail and your phone never see what you sent from the PC. Check File, Account Settings, the account, Change, More Settings, Sent Items tab (or Folders, depending on version) and choose Save sent items in the following folder on the server, selecting Sent. If the server folders do not appear, right-click the account in the folder list, choose IMAP Folders, Query, and subscribe to Sent, Drafts and Trash.

If something goes wrong

• "Cannot connect to the incoming (IMAP) server" or error 0x800CCC0E: the server name is not mail.oqumail.com or the port and encryption do not match (993 with SSL/TLS).
• Sends fail with 0x800CCC80 or "The server rejected the sender address": outgoing authentication is off. Tick it under Outgoing Server.
• "The server you are connected to is using a security certificate that cannot be verified": wrong host name; do not click Yes, fix the name. See certificate errors.
• Password prompts repeat: the user name must be the full address. Remove the account and add it again through Control Panel, Mail.
• Mail arrives slowly: Send/Receive, Send/Receive Groups, Define, set the schedule to every 5 minutes.

Common questions

Classic or new Outlook?

Classic is the one with the ribbon and File menu; the new Outlook has a toggle at the top right and syncs IMAP accounts through Microsoft's cloud. If you want the mailbox to connect directly from your PC, stay on classic; the new Outlook guide covers the other.

Why does Outlook show a Root folder path setting?

Some servers nest folders under INBOX. OquMail does not; leave Root folder path empty.

Can I keep my old PST archive?

Yes. The IMAP account and a local PST file sit side by side in the folder list; drag old mail into the new account if you want it on the server.