Reading time: 7 min · Last verified: July 2026 · SMTPedia editorial team
AT&T email covers the @att.net, @sbcglobal.net, @bellsouth.net, @ameritech.net, @pacbell.net, and other legacy telecom-era domains that AT&T consolidated on shared mail infrastructure. Since 2019, AT&T requires a “Secure Mail Key” (functional equivalent of an app-specific password) for third-party mail clients. The regular account password will not authenticate through Outlook, Thunderbird, or Apple Mail.
AT&T rejects your regular account password when connecting from third-party clients. Generate a “Secure Mail Key” from currently.att.yahoo.com or the AT&T account portal (Profile, Sign-in info, Secure mail key). Copy the generated key and paste it into the mail client’s password field. Use a distinct key per client (Outlook, Thunderbird, iOS Mail) rather than sharing one string across devices. Reference: SMTP 550 5.7.1 guide.
Quick Reference: AT&T Server Settings
Configure the mail client with the values below. The password field takes the AT&T Secure Mail Key, not the account password. All legacy AT&T domains (att.net, sbcglobal.net, bellsouth.net, ameritech.net, pacbell.net) use the same server settings.
| Protocol | Server | Port | Encryption | Authentication |
|---|---|---|---|---|
| SMTP (outgoing) | smtp.mail.att.net | 465 (SSL) or 587 (STARTTLS) | Required | Full email + Secure Mail Key |
| IMAP (incoming, recommended) | imap.mail.att.net | 993 | SSL/TLS | Full email + Secure Mail Key |
| POP3 (incoming, single device) | inbound.att.net | 995 | SSL/TLS | Full email + Secure Mail Key |
AT&T SMTP Settings (Sending Mail)
SMTP handles outbound mail. Use smtp.mail.att.net on port 465 with SSL/TLS or 587 with STARTTLS. Username is your full AT&T email address (att.net, sbcglobal.net, bellsouth.net, ameritech.net, or pacbell.net); password is the Secure Mail Key generated for this client.
If authentication fails, verify three things: the username is the full email address; the Secure Mail Key is entered without spaces (Outlook occasionally strips trailing characters on paste); and the key has not been revoked from another session. AT&T Secure Mail Keys can be regenerated at any time without affecting the account password.
AT&T IMAP Settings (Recommended for Reading)
IMAP synchronizes message state across all configured devices. Use imap.mail.att.net on port 993 with SSL/TLS. Same Secure Mail Key authentication as SMTP.
Because AT&T mail runs on Yahoo Mail infrastructure (through a long-standing partnership), the folder structure follows the Yahoo scheme (Inbox, Sent, Drafts, Spam, Trash). Custom folders created via webmail sync to IMAP; Thunderbird and older clients may require explicit subscription for non-standard folders to appear.
AT&T POP3 Settings (Single-Device Access)
POP3 downloads mail to a single device. Use inbound.att.net on port 995 with SSL/TLS. Same Secure Mail Key authentication as SMTP and IMAP.
Enable “Leave messages on server” in the client’s POP3 advanced settings if you want to preserve mail for AT&T webmail access or other devices. Otherwise mail downloaded to device A is removed from the server. Given AT&T mail runs on Yahoo infrastructure with generous storage quotas, using IMAP for most 2026 setups is a better choice.
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.
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About AT&T Mail
att.netsbcglobal.net · bellsouth.net · pacbell.net · ameritech.net · flash.net · prodigy.net · swbell.netAT&T Mail is the email service historically provided to AT&T internet subscribers across multiple decades and corporate iterations. The service portfolio inherited domains from various regional ISPs merged into AT&T over time: SBC Global, BellSouth, Pacific Bell, Ameritech, Prodigy, and others.
Since 2017, AT&T Mail has been operated in partnership with Yahoo, running on Yahoo's email infrastructure (yahoo.com backend). This means IMAP, POP3, and SMTP settings for @att.net, @sbcglobal.net, @bellsouth.net, and related domains use the same Yahoo endpoints (imap.mail.yahoo.com, smtp.mail.yahoo.com).
The service serves an estimated 20+ million active mailboxes across all legacy AT&T-affiliated domains. Long-tenured @sbcglobal.net and @bellsouth.net addresses from the early 2000s continue to function; these often carry significant legacy trust weight in email deliverability signals.
Timeline
- 1985AT&T Mail history begins with early online services
- 2005SBC acquires AT&T; consolidates BellSouth domains
- 2017AT&T Mail infrastructure moved to Yahoo backend
- 2020sLegacy domains continue on Yahoo/AT&T shared infrastructure
AT&T Mail operates one of the largest portfolios of legacy US ISP email domains (7+ active domains). The 2017 migration to Yahoo's infrastructure means that AT&T Mail deliverability follows Yahoo's bulk sender rules (2024 SPF/DKIM/DMARC + one-click unsubscribe requirements for high-volume senders).
Frequently Asked Questions
How do I generate an AT&T Secure Mail Key?
Log into currently.att.yahoo.com or the AT&T account portal at att.com, go to Profile, then Sign-in info, then “Manage secure mail key.” Click “Add secure mail key,” name it (e.g., “Outlook home laptop”), and copy the generated key into the mail client’s password field. Use one key per client rather than sharing across devices.
Do @sbcglobal.net, @bellsouth.net, and other legacy domains use the same servers?
Yes. AT&T consolidated all legacy telecom-era email domains (Southwestern Bell / SBCGlobal, BellSouth, Ameritech, Pacific Bell, Prodigy, SNET) onto shared infrastructure. Use smtp.mail.att.net, imap.mail.att.net, and inbound.att.net for all of them with your full legacy address as the username and a Secure Mail Key as the password.
Why does AT&T reject my regular account password?
Since 2019 AT&T requires Secure Mail Keys for third-party mail client access. This is a security measure to reduce the impact of a compromised main account password: the Secure Mail Key is scoped to mail client access only and can be revoked without changing the main account password.
Does AT&T email support OAuth2?
No. AT&T supports only the Secure Mail Key mechanism for third-party client SMTP/IMAP/POP3 authentication. OAuth2 is not implemented on the smtp.mail.att.net or imap.mail.att.net endpoints.
Which SMTP port works when 587 is blocked?
Switch to port 465 with implicit SSL/TLS. US corporate networks and some mobile carriers block outbound 587 but leave 465 accessible. Both ports use the same Secure Mail Key authentication.
About This Guide
The AT&T server settings on this page were last verified in July 2026 against AT&T customer support documentation and the Yahoo Mail postmaster guidance for AT&T-branded infrastructure. The Secure Mail Key requirement has been stable since 2019 and applies to all legacy AT&T telecom domains (sbcglobal.net, bellsouth.net, ameritech.net, pacbell.net, and others). SMTPedia re-verifies these settings quarterly. If you find a discrepancy between what is documented here and what AT&T currently requires, please report it so we can update the reference.
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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