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Ultra Emailerby Code Craft
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SMTP setup

SMTP settings for bulk email: connect your provider

Ultra Email has presets for 100+ servers that fill in the host, port and security. These pages cover the part a preset cannot: where to find your password or key.

Mailbox

Business and domain mail

Sending service

Set up SPF, DKIM and DMARC

Gmail and Yahoo expect bulk senders to publish all three on the sending domain.

SPF
One TXT record on your domain listing every service that sends for you, for example v=spf1 include:_spf.google.com include:amazonses.com ~all. Only one SPF record per domain.
DKIM
Turn on DKIM signing at your provider (Google Admin, Hostinger, SES, SendGrid and others) and add the DNS records they give you.
DMARC
A TXT record at _dmarc.yourdomain.com. Start with v=DMARC1; p=none; rua=mailto:you@yourdomain.com, then move to p=quarantine once reports look clean.

The app has a Domain health tool that reads these records for you. See the email deliverability tools.

When the test email fails

535 Authentication failed, Invalid login, Username and Password not accepted

Wrong password type. Use an app password for Gmail, Yahoo, Outlook, iCloud and AOL, and the full email address as the username.

ETIMEDOUT, Connection timeout

The port is blocked by your network or antivirus. Try 587 instead of 465, or the reverse, and allow Ultra Email in your firewall. Many internet providers block port 25, so do not use it.

self-signed certificate, TLS errors

Use the host name your provider gives you (not an IP address) and the matching pair: 465 is SSL, 587 is STARTTLS.

550 Relaying denied, Sender address rejected

The From email must be the mailbox you log in with, or a verified alias or verified domain in your relay.

421, 454, Daily user sending limit exceeded

The provider's limit was reached. Lower the hourly limit, add more senders, or wait 24 hours.

Test works but campaign emails land in Spam

Set up SPF, DKIM and DMARC, warm up slowly, avoid spammy wording and include a plain-text version.

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