SMTP sends mail. IMAP and POP3 receive it. That's the whole split: when you set up an email client, you'll configure an outgoing (SMTP) server and an incoming (IMAP or POP3) server separately, and they don't have to match in any special way beyond both pointing at your mail host.
For incoming mail, use IMAP unless you have a specific reason not to. It keeps your mailbox in sync across every device. See POP3 vs IMAP, which should I use? for the full comparison.
SMTP: the outgoing protocol
SMTP (Simple Mail Transfer Protocol) is how your email client hands a message off to a mail server, and how mail servers relay messages to each other. It's a one-way push: your client connects, authenticates, and submits the message. The server queues it and passes it along until it reaches the recipient's mail server.
Typical SMTP settings for a hosted mailbox:
- Server: check your welcome email or hosting control panel for the exact hostname
- Port:
465(SSL) or587(STARTTLS) - Authentication: required, same username and password as your incoming mail
- Username: the full email address, not just the local part
Receiving servers also check SPF and DKIM records when deciding whether to trust a message instead of marking it spam. If outgoing mail is failing rather than just slow: work through Why can't I send email? first. It covers port blocks, authentication errors, and rejected recipients step by step.
IMAP: mail stays on the server
IMAP (Internet Message Access Protocol) treats the server as the permanent home for your mail. Your client displays what's there and mirrors any changes back: read a message on your phone, and it shows read on your laptop too. Folders, flags, and deletions all sync the same way.
Standard IMAP settings:
- Server: check your welcome email or hosting control panel for the exact hostname
- Port:
993(SSL)
Because messages live on the server, search is fast even across years of mail, and the server holds a backup independent of any one device. This is the right default for anyone checking email from more than one device.
POP3: mail moves to your device
POP3 (Post Office Protocol v3) downloads messages to your device and, in its classic configuration, removes them from the server afterward. Your device becomes the single copy. There's no sync between devices, no shared folder state, nothing left on the server to search or fall back on if your local copy is lost.
POP3 still has a few legitimate uses: tight mailbox storage limits; a single device that handles all mail; or a workflow that wants messages archived locally rather than kept server-side. Outside of those cases, it creates more friction than it saves.
Putting it together in a mail client
A typical client setup asks for both halves at once. You'll enter:
- An incoming server (IMAP on
993, or POP3 on your mail provider's configured port) - An outgoing server (SMTP on
465or587) - One username and password, used for both
Getting the incoming protocol right determines search, multi-device access, and backups. Getting SMTP right means outgoing mail authenticates cleanly and reaches inboxes instead of spam folders.
If your settings match the above and mail still won't send or receive, open a ticket from the portal. It reaches real people, not a queue.