SMTP settings lookup: server, port and encryption for any email address
SMTP settings are the outgoing server host, port, encryption and login an app needs to send mail as you. For Gmail they are smtp.gmail.com on port 465 (SSL/TLS) or 587 (STARTTLS); for Microsoft 365, smtp.office365.com on 587. Enter any address or domain and this tool finds its provider from the MX records and shows the settings from that provider's documentation.
A domain is matched by its MX records from public DNS. Nothing connects to a mail server. 10 lookups a minute.
Sample result
Google Workspace runs this domain's mail; send via smtp.gmail.com on port 587.
- Detected from MX
- Google Workspace
- SMTP
- smtp.gmail.com:587 STARTTLS
- IMAP
- imap.gmail.com:993
What this means for you
Paste these settings into your email app or sending tool to connect the mailbox.
- Detects the mail host from MX records
- SMTP, IMAP and POP hosts, ports, security
- 19 providers, each linked to its own docs
- Or pick a provider from the list
- SMTP
- IMAP
- POP
By SimpleVerifier Team · Last updated
How do I find the SMTP settings for my email address?
- Type your email address or domain, such as you@yourcompany.com, and press Find SMTP settings. Or pick a provider from the list.
- The tool reads the domain's MX records from public DNS to see who hosts the mailboxes, and uses the SPF record when a security gateway sits in front.
- Copy the SMTP host, port and encryption into your app, printer or sending tool, with the username and password type shown.
- Check the linked provider page if a setting is rejected; providers change authentication rules more often than hosts and ports.
Example
- You enter
- An address at a domain whose MX records point to Google, or Gmail picked from the provider list.
- You get
- Detected as Google Workspace. SMTP:
smtp.gmail.comon 465 (SSL/TLS) or 587 (STARTTLS); IMAP:imap.gmail.comon 993; username: your full Gmail or Workspace address, with a link to Google's own documentation. - Limits
- Picking a provider from the list needs no lookup; detecting it from a domain is one MX lookup, 10 a minute per connection. It doesn't sign in to any server.
What are SMTP server settings?
They are the five values a mail client or app needs to send through your provider: the SMTP host name, the port, the encryption (SSL/TLS or STARTTLS), the username and how you authenticate. Incoming mail uses separate IMAP or POP settings. All three protocols are standard; SMTP itself is RFC 5321, and sending from an app on port 587 is the message submission of RFC 6409.
The values come from your mailbox provider, not your domain registrar or website host, which is why the tool starts from the MX records. A domain on Google Workspace uses Google's servers whatever its web address.
What are the SMTP settings for Gmail?
smtp.gmail.com, port 465 with SSL/TLS or port 587 with STARTTLS, your full address as the username, and Sign in with Google or an app password for authentication. Incoming mail is imap.gmail.com on 993 or pop.gmail.com on 995, per Google's IMAP, POP and SMTP page. Google no longer accepts your normal account password from third-party apps; an app that can't do Sign in with Google needs an app password, which requires 2-Step Verification.
Printers and line-of-business apps on a Workspace domain can use the SMTP relay instead, smtp-relay.gmail.com, which an admin turns on and which can authenticate by IP address. Google covers both in send email from a printer, scanner or app.
What are the SMTP settings for Office 365?
smtp.office365.com on port 587 with STARTTLS, signed in with the mailbox's own account. Microsoft's guide to sending from a device or application says a device that defaults to port 465 doesn't support the TLS versions Microsoft 365 needs. Personal Outlook.com, Hotmail and Live accounts use smtp-mail.outlook.com on 587 instead.
If the settings are right and sign-in still fails, SMTP AUTH is probably off. Microsoft lets admins disable SMTP AUTH for the organization or per mailbox and recommends it where nothing needs it, so ask an admin to enable it for the mailbox that sends.
Which SMTP port should I use: 25, 465 or 587?
Use 587 with STARTTLS or 465 with SSL/TLS to send from an app; use 25 only between mail servers. Port 25 is where servers relay mail to each other, and many ISPs and cloud providers block it outbound, as our note on cloud providers blocking port 25 explains. 465 starts encrypted from the first byte; 587 starts in plain text and upgrades with the STARTTLS command.
Both encrypt the connection. Pick the one your provider lists; when both are offered, either works.
SMTP port 25 vs 465 vs 587
| 25 | 465 | 587 | |
|---|---|---|---|
| Used for | Server to server | App submission | App submission |
| Encryption | Optional STARTTLS | Implicit TLS from the start | STARTTLS upgrade |
| Login required | No (relay) | Yes | Yes |
| Often blocked outbound | Yes, by ISPs and clouds | Rarely | Rarely |
Who uses this tool, and for what?
- Cold emailers
- Connect a Workspace or Microsoft 365 mailbox to an outreach tool without hunting through admin docs for the host and port.
- IT and office admins
- Set up a scanner, printer or app to send mail, and see whether a client's domain sits behind a gateway first.
- Developers
- Get the SMTP endpoint and the username convention (apikey, resend, SES credentials) for a transactional email service.
- Agencies
- Find which provider hosts a client's mail from the domain alone, then hand them the right settings.
What can’t this tool tell you?
- It shows documented settings; it doesn't connect to any server, so it can't confirm your account can sign in.
- Behind a security gateway the mailbox provider is inferred from SPF and can be wrong.
- Web-hosting and self-hosted mail servers vary; we show only providers whose own docs we've checked.
- Providers change authentication rules (app passwords, OAuth, SMTP AUTH) more often than hosts and ports; the linked source is the authority.
Common questions
- How do I find my SMTP server settings?
- Find who hosts your mailbox, then use that provider's settings. Enter your address in the tool above: it reads your domain's MX records and shows the matching SMTP host, port and encryption.
- What is the SMTP server for Gmail?
- smtp.gmail.com, on port 465 (SSL/TLS) or 587 (STARTTLS), with your full Gmail or Workspace address as the username and Sign in with Google or an app password to authenticate.
- What are the SMTP settings for Office 365?
- smtp.office365.com, port 587, STARTTLS, with the sending mailbox's own sign-in. SMTP AUTH must be enabled for that mailbox, which an admin can switch on.
- What are the SMTP settings for Outlook.com and Hotmail?
- smtp-mail.outlook.com on port 587 with STARTTLS, per Microsoft. Incoming IMAP is outlook.office365.com on port 993.
- What are the SMTP settings for Yahoo Mail?
- smtp.mail.yahoo.com, port 465 or 587 with SSL, your full Yahoo address and an app password generated in Yahoo's account security settings.
- Is SMTP port 587 secure?
- Yes, when the client issues STARTTLS, which upgrades the connection to TLS before the password is sent. Most providers require STARTTLS on 587.
- Is SMTP port 465 secure?
- Yes. Port 465 uses implicit TLS: the connection is encrypted from the start. Microsoft 365 asks for 587 instead.
- How do I test SMTP settings?
- Send a test message from the app you configured. This tool doesn't connect to mail servers; it gives you the documented settings to enter.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
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- Hard bounces removed before a send, not discovered after
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