Fastmail addresses (@fastmail.com, @fastmail.fm, @fastmail.us, plus any custom domain hosted on Fastmail) work with any standard mail client via IMAP, POP3, and SMTP. The single gotcha in 2026 is authentication: two-factor accounts (which is nearly every account by default) require an app password generated from the Fastmail dashboard, not the regular login password. This guide covers the exact server settings, the app-password flow, and the paid-only model (Fastmail has no free tier since 2020).
Setup gotcha
App password requiredPaid plans only
Fastmail requires an app password for every third-party client (Outlook, Thunderbird, Apple Mail, mobile, or SMTP relay) once two-factor authentication is enabled on the account, which is the default. Your regular Fastmail login password will not authenticate against IMAP or SMTP under 2FA. Generate an app password at Fastmail Settings then Privacy & Security then App Passwords, then paste it in place of the login password. Reference: SMTP authentication.
Quick reference: Fastmail server settings
All three protocols require SSL/TLS and full-address authentication. Custom-domain mailboxes hosted on Fastmail use the same hostnames as native @fastmail.com addresses.
| Protocol | Server | Port | Encryption | Auth |
|---|---|---|---|---|
| SMTP | smtp.fastmail.com | 465 or 587 | SSL/TLS or STARTTLS | Full address + app password |
| IMAP | imap.fastmail.com | 993 | SSL/TLS | Full address + app password |
| POP3 | pop.fastmail.com | 995 | SSL/TLS | Full address + app password |
Fastmail SMTP settings
Fastmail SMTP uses smtp.fastmail.com on port 465 with implicit SSL/TLS. Port 587 with STARTTLS is also supported and useful when 465 is blocked. Authenticate with the full email address (native @fastmail.com or a custom domain address) and an app password generated in the Fastmail dashboard. The regular login password will not work under 2FA, which is enabled on all accounts by default.
Fastmail also supports JMAP as a modern alternative to IMAP for the small but growing set of clients that speak it (Fastmail’s own web and mobile apps use JMAP internally). JMAP uses a REST-like API instead of the IMAP wire protocol and does not replace SMTP for outbound. For every mainstream client (Outlook, Thunderbird, Apple Mail, iOS Mail, Android Mail), IMAP + SMTP as documented above is the setup path.
Fastmail IMAP settings
Fastmail IMAP uses imap.fastmail.com on port 993 with SSL/TLS. Same full-address username; same app password. IMAP keeps mail on the server and syncs folder state across every device. Fastmail preserves folder hierarchy under a single top-level INBOX, with the Archive, Sent, Drafts, Junk, and Trash folders exposed as standard IMAP folders.
Storage is per plan: Basic 2 GB, Standard 30 GB, Professional 100 GB. Files stored in Fastmail Files (the built-in file storage) count against the same quota. Custom domain mailboxes on the same account share the plan quota.
Fastmail POP3 settings
Fastmail POP3 uses pop.fastmail.com on port 995 with SSL/TLS. POP3 downloads messages to a single device and removes them from the server unless the client is configured to leave a copy. This works for single-device users but breaks the moment the same account is checked from two devices. IMAP is the recommended incoming protocol for every other case.
Fastmail permits POP3 to specific device names to prevent accidental download of the same message twice when both a laptop and a phone are configured against the same account. This device-name behavior is configured in the Fastmail dashboard under Settings then POP Links.
Fastmail plans and pricing
Fastmail is paid-only. The free plan was discontinued in 2020. All new accounts start with a 30-day free trial (no credit card) that gives access to Standard plan features. Prices are $3/month (Basic), $5/month (Standard, most popular), or $9/month (Professional) on annual billing, dropping from the monthly rate. Business plans (custom domain team seats) start at $5/user/month.
IMAP, POP3 and SMTP Integration into Gmail
Configure Gmail with external IMAP/POP3/SMTP to send/receive emails from your custom domain through Gmail’s interface. Perfect for professionals managing multiple accounts in one place.
- Google Account β Security β App passwords (2-Step Verification must be enabled).
- Generate App Password for “Mail” β copy 16-character password.
- Gmail β Settings β See all settings β Forwarding and POP/IMAP.
- Enable IMAP β Save Changes.
- Incoming (IMAP):
[IMAP SERVER]:993 SSL| Outgoing (SMTP):[SMTP SERVER]:587 STARTTLS. - Use your full email + App Password (not regular password) for authentication.
β Gmail Result: Send/receive custom domain email directly in Gmail interface with full search/folder integration.
WordPress SMTP Plugin Configuration (WP Mail SMTP + MailPoet)
Configure SMTP in WordPress to fix email delivery issues and prevent spam folder placement. WP Mail SMTP and MailPoet ensure reliable transactional emails, contact forms, and newsletters deliver successfully.
- Install and activate WP Mail SMTP or MailPoet plugin from your WordPress dashboard.
- Navigate to WP Mail SMTP β Settings or MailPoet β Settings β Sending tab.
- Select “Other SMTP” as your mailer method from the dropdown.
- Enter SMTP settings with Port
587and STARTTLS encryption (when available). - Input your full email address and password in the authentication fields.
- Click Save Settings and send a test email to verify the configuration works.
β Result: WordPress contact forms, user registrations, and newsletter emails now deliver reliably via your SMTP server.
This configuration includes these plugins and tools within WordPress:
- HappyForms
- Elementor Forms
- Gravity Form
- WooCommerce Checkout Form
- Contact Form by BestWebSoft
- Fluent Forms
- Contact Form 7
- WPForms
- Ninja Forms
- Default WordPress Reg Form
- Forminator Forms
- Formidable Form
- WordPress Comment Form
- Mail Mint Form
Thunderbird OAuth2 Email Setup (IMAP + SMTP)
Secure IMAP & SMTP using OAuth2 token authentication in Thunderbird. This modern method eliminates password storage for enhanced security.
- Open Thunderbird β Account Settings β Account Actions β Add Mail Account.
- Enter your email address and click Continue to begin setup.
- Select IMAP protocol and choose OAuth2 authentication method.
- Thunderbird opens a browser window β log in to your provider β Grant access permissions.
- Automatic configuration applies: Incoming: use the IMAP server address from the settings table above, port 993, SSL
- Click Done β Thunderbird begins syncing folders and emails immediately.
OAuth2 advantage: Token-based authentication enhances security over traditional password methods while maintaining full functionality.
Outlook IMAP, POP3 & SMTP Setup (Auto + Manual)
Outlook configuration supports both automatic server detection and manual IMAP/POP3/SMTP settings for complete control over your email setup.
π Auto Setup (Recommended):
- Go to File β Add Account β Enter your email address + password.
- Outlook automatically detects IMAP, POP3, and SMTP server settings.
- Click Connect β setup completes in approximately 30 seconds.
βοΈ Manual Setup (Advanced Users):
- Authentication: Use your full email address + password for both servers
BlueMail Two-Factor Authentication + OAuth2 Setup
BlueMail security setup combines OAuth2 authentication with two-factor authentication (2FA) for maximum account protection.
- Open BlueMail β Account Settings β Security β Enable Two-Factor Authentication.
- Link your phone number or authenticator app for 2FA verification codes.
- Add email account β Choose OAuth2 or manual server configuration.
- Enter server details from the table above
- Complete login with 2FA code β enhanced security layer activated.
Apple Mail IMAP Configuration (iCloud + Manual)
Setup IMAP in Apple Mail for seamless synchronization across Mac, iPhone, and iPad devices with full folder support.
- Open Apple Mail β Mail β Add Account β Other Mail Account.
- Enter your name, email address, and password β click Continue.
- Select IMAP account type β Incoming server.
- Next: Outgoing server
- Click Sign In β Mail verifies settings and begins folder synchronization.
iOS Mail App Setup (iPhone/iPad)
iPhone/iPad Mail configuration syncs IMAP folders across all Apple devices with native push notifications.
- Go to Settings β Mail β Accounts β Add Account β Other.
- Enter name, email, password β Next.
- Account Type: IMAP β Incoming:
[IMAP SERVER]Port993SSL. - Enter your outgoing SMTP server and port.
- Next β Save β iOS verifies and syncs immediately.
Push enabled automatically: new emails appear instantly on Lock Screen.
Android Mail App Configuration
Android Gmail/Email app setup works with any IMAP/SMTP provider for native device integration.
- Go to: Settings β Accounts β Add Account β Email (or Gmail app).
- Enter email + password β Next.
- Account Type: IMAP
- Outgoing server details β Require authentication.
- Next β Sign In β Android syncs contacts/calendar if enabled.
Sync interval: 15min default (battery optimized) – change in Account Sync settings.
eM Client Manual IMAP & POP3 Sync Configuration
Configure your email settings on eM Client with either automatic setup or through precise IMAP/POP3 server settings for reliable email synchronization and full folder support.
- Click New Account β Mail
Authentication requires full email address + password for both incoming and outgoing servers.Click Next β Finish β Send/Receive All Folders to begin synchronization.
Mailbird OAuth2 IMAP & SMTP Integration
Secure Mailbird setup using OAuth2 authentication eliminates password storage while providing full IMAP/SMTP functionality.
- Mailbird β Add Account β Enter your email address to begin.
- Choose Manual Setup β OAuth2 authentication method from options.
- Browser opens your provider’s login page β enter credentials β Authorize Mailbird.
- Mailbird receives access token and automatically configures IMAP/SMTP servers.
- Setup completes β full email synchronization begins automatically.
Mailspring OAuth2 IMAP Configuration
Mailspring OAuth2 setup provides secure email access without storing passwords directly in the application.
- Add new email account β Select Custom IMAP configuration option.
- Incoming
IMAP SERVERand outgoingSMTP SERVER. - Mailspring prompts OAuth2 authorization via browser window for secure login.
- Log into your provider account and grant Mailspring access permissions.
- Mailspring automatically manages authentication tokens β seamless email access established.
Postbox Manual IMAP Synchronization
Postbox IMAP setup with manual synchronization control for precise email folder management and immediate updates.
- Add IMAP account β Enter IMAP Server details.
- Outgoing SMTP with full email authentication.
- Postbox connects and displays folder structure automatically.
- Right-click any folder β Get Messages for immediate manual synchronization.
- Manual sync updates local mailbox instantly with server changes (read status, deletions, organization).
SendBlaster SMTP Configuration (Bulk Email)
Bulk email SMTP configuration in SendBlaster requires precise server authentication for reliable campaign delivery.
- Open SendBlaster β Settings β SMTP Configuration section.
- Enter SMTP Server and Port: do not forget to Enable TLS encryption.
- Authentication: Your full email address + password (required).
- Click Test Connection β verify green success indicator appears.
- Save settings β SendBlaster ready for bulk email campaigns and newsletters.
MailJerry IMAP Real-Time Synchronization
MailJerry IMAP setup enables real-time access to email folders stored on your provider’s server across all devices.
- Incoming Server and encryption required.
- Authentication: Full email address + password for secure connection.
- Enable real-time folder synchronization settings in MailJerry preferences.
- Folders update instantly with new messages, read status, and deletions across devices.
Clean.email OAuth2 Synchronization Setup
Clean.email OAuth2 setup provides secure mailbox access without sharing passwords directly with the application.
- Add new account β Select OAuth2 authorization method.
- Your provider opens login portal β enter credentials securely.
- Grant Clean.email permissions for email read/write access.
- OAuth2 token enables real-time message management, filtering, and organization.
- Setup complete β Clean.email maintains secure, ongoing mailbox synchronization.
Common IMAP/POP3/SMTP Troubleshooting
- Authentication failed: Always use your complete email address, never just the username portion.
- Port blocked by ISP: Try alternative SMTP port as fallback.
- SSL certificate errors: Ensure certificate validation is enabled in client settings.
- Slow or no IMAP sync: Check folder subscriptions and enable all folders in client settings.
More Popular Email Settings Guides
| Guide | Region | Type |
|---|---|---|
| T-Online.de SMTP Settings | π©πͺ Germany | ISP |
| Fibertel.com.ar Webmail | π¦π· Argentina | ISP |
| QQ Mail SMTP Server | π¨π³ China | Global |
| Volny Mail Settings | π¨πΏ Czech Republic | ISP |
| Freemail.hu IMAP Settings | ππΊ Hungary | Regional |
| Etisalat/EIM Mail Settings | π¦πͺ UAE | ISP |
| Hotmail IMAP Settings | π Global | Global |
| 126.com IMAP Server Settings | π¨π³ China | Regional |
| Waoo Mail SMTP/IMAP | π©π° Denmark | ISP |
| GMX SMTP Server Settings | π Global | Global |
| 163.com IMAP Server Settings | π¨π³ China | Regional |
| Webmail.co.za IMAP Settings | πΏπ¦ South Africa | Regional |
Frequently asked questions
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Sign in at fastmail.com, go to Settings then Privacy & Security then App Passwords, click New App Password, name it (Thunderbird, Outlook, iPhone, etc.), and copy the generated string. Paste that string into the mail client in place of the regular password. Each mail client should get its own app password so you can revoke access to a single client without affecting the others.
Does Fastmail still have a free plan?
No. The free plan was discontinued in 2020. All new accounts get a 30-day free trial with access to Standard plan features and no credit card required. After 30 days, the account must be on a paid plan to keep sending and receiving.
Can I use a custom domain with Fastmail?
Yes on Standard and Professional plans. Configure the domain in the Fastmail dashboard under Settings then Domains, follow the DNS setup (MX, SPF, DKIM), and provision addresses under the custom domain. Custom domain mailboxes use the same server hostnames as native @fastmail.com addresses (imap.fastmail.com, smtp.fastmail.com).
What is JMAP and should I use it?
JMAP is a modern REST-based protocol developed largely by Fastmail as a successor to IMAP. It is more efficient over mobile networks and supports richer sync semantics. Only a small number of clients speak JMAP (Fastmail’s own apps, Aerc, some experimental Thunderbird plugins). For every mainstream client, use IMAP + SMTP as documented.
How does Fastmail compare to other paid privacy providers?
Fastmail (Australia) uses standard protocols without server-side encryption but with strong operational privacy and legal jurisdiction. Proton Mail (Switzerland) offers default end-to-end encryption but requires the Bridge app for third-party clients. Mailbox.org and Posteo (Germany) offer standard protocols with optional PGP at lower entry prices. Choose Fastmail for the best mainstream mail client experience without a bridge; choose the others when default encryption or lower price matters more.
What happens if the Fastmail app password stops working?
App passwords do not expire automatically. If a client suddenly fails to authenticate, the most common cause is that the app password was revoked in the Fastmail dashboard (which can happen accidentally when cleaning up old device entries). Regenerate a new app password in Settings then App Passwords and update the client.
Where is Fastmail webmail?
Webmail is at fastmail.com. Log in with the full email address and the regular login password (not the app password). App passwords are only for mail clients, not for webmail. Two-factor authentication protects the login and cannot be disabled on the recommended path.
About this guide
These Fastmail server settings were verified against Fastmail’s official documentation at fastmail.com/help in July 2026. Hostnames and ports have been stable since the early 2010s. Plan tiers were last restructured in 2020 (removal of the free plan) and confirmed in 2026 pricing. SMTPedia re-verifies each provider quarterly.
About the Author
Alaa Β· LinkedIn
Email infrastructure specialist with 8+ years of hands-on experience in SMTP, deliverability, and email verification. Iβve configured and troubleshot mail systems across Postfix, Exchange, and cloud relays, managed IP reputation and warmup campaigns, and built verification pipelines processing millions of addresses. My work spans DNS authentication (SPF, DKIM, DMARC, BIMI), bounce handling, blocklist monitoring, and compliance frameworks including CAN-SPAM and GDPR. I write every article on SMTPedia to give email professionals, developers, and marketers the accurate, RFC-grounded reference they need.
About SMTPedia
SMTPedia is an independent email industry reference covering SMTP, IMAP, POP3, email deliverability, marketing platforms, DNS authentication, and email verification. Every article is researched from official provider documentation, IETF RFCs, and industry best practices. Settings and configurations are verified quarterly.
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