SMTP Server Settings for Every Email Provider

An SMTP server is the outgoing half of an email account: the address your mail app, phone, printer or website hands messages to so they can be sent. Every provider runs its own, and each one expects a specific server name, port and encryption setting. Get any of the three wrong and messages sit in the outbox while incoming mail keeps working perfectly.

The table below lists the SMTP settings for every major provider, each checked against that provider's own documentation. Underneath it you'll find the two things that cause most sending failures: pairing the wrong encryption with a port, and using a password the provider no longer accepts.

Using a work or custom-domain address? Enter it in the Email Settings Finder. It reads the domain's mail records and tells you whether it runs on Google Workspace, Microsoft 365 or another host.

SMTP settings by provider

In every case the SMTP username is the full email address unless the provider's guide says otherwise, and authentication must be switched on for the outgoing server. Many mail apps store the outgoing password separately from the incoming one, so updating only one leaves sending broken.

587, 465 or 25: which port to use

Three ports come up in SMTP settings. Only two of them are meant for mail apps.

The most common mistake: mismatched port and encryption

The port and the encryption setting are a pair. Choose them together:

• Port 587 → STARTTLS (sometimes labelled "TLS").
• Port 465 → SSL/TLS (sometimes labelled "SSL").

Mixing them doesn't work. On port 465 the server expects encryption from the very first byte, while STARTTLS begins unencrypted and upgrades afterwards (RFC 8314). Port 465 with STARTTLS, or port 587 with SSL/TLS, typically ends in a timeout or a handshake error even though the server name is right. If you change one setting, change the other with it.

So which should you pick?

Use the provider's first-listed port from the table above. If it times out on your network, switch to the provider's other documented port and its matching encryption. Two exceptions: Microsoft 365 doesn't accept port 465 at all, and Outlook.com documents only 587.

Whichever port you use, the connection must support modern TLS. The email standard requires servers to support TLS 1.2 or later (RFC 8314). GMX accepts only TLS 1.2 and 1.3, and Microsoft 365 requires TLS 1.2 or 1.3, so older printers and apps that can't do TLS 1.2 won't connect.

Why the SMTP password is refused

Most providers no longer accept your normal account password in a third-party app. What they expect instead:

• Sign-in window (OAuth). Outlook.com requires it. Gmail recommends "Sign in with Google" and treats app passwords as a fallback only for eligible accounts with 2-Step Verification. Choose the app's built-in Google or Microsoft account type rather than "Other / IMAP".
• App password. Yahoo, AOL, iCloud (an "app-specific password"), Fastmail and Yandex expect a generated password made in your account's security settings. Use one per app so you can revoke it on its own.
• A switch on the server. Microsoft 365 needs SMTP AUTH enabled for that mailbox by an administrator. GMX and mail.com need POP3/IMAP access turned on in their settings first, and mail.com offers it only on Premium.

Work and custom-domain email

A company address like you@yourcompany.com uses the SMTP server of whoever hosts the domain, not one tied to the domain name:

• Google Workspace: smtp.gmail.com, signing in with the full Workspace address. For printers, scanners and apps, Google also documents smtp-relay.gmail.com (ports 25, 465 or 587, authenticated by IP address).
• Microsoft 365: smtp.office365.com on 587. See the Microsoft 365 SMTP guide for turning on SMTP AUTH and for relay options.
• Paid Zoho Mail organisation accounts on their own domain: smtppro.zoho.com rather than smtp.zoho.com.
• Anything else: run the address through the Email Settings Finder, or ask whoever manages the domain.

Providers that work differently

• Proton Mail has no public SMTP server. Desktop apps send through Proton Mail Bridge, a paid-plan app that runs on your own computer, which is why its server is 127.0.0.1. Use the port and credentials Bridge shows you.
• Tuta offers no SMTP, IMAP or POP access at all.
• GMX addresses ending in gmx.net use mail.gmx.net rather than mail.gmx.com.
• iCloud uses a different username for each direction: just the name part for incoming IMAP, but the full address for outgoing SMTP.
• Zoho accounts hosted in Europe, India or Australia may need a regional server name, shown inside Zoho Mail's settings.

Published sending limits

Only some providers publish a number. These are the ones stated in official documentation:

Other providers apply limits without publishing a figure in the pages we checked, so we don't quote one. For newsletters or bulk sending, use a service built for it rather than a personal mailbox.

If mail still won't send

Each provider guide linked in the first table has a fuller checklist for that service. Got a bounce with an error number? Look it up in SMTP error codes explained.