SMTP errors can arise from various issues: mismatched sender and username, oversized messages, blacklisted receivers, or temporary server limits. To resolve, ensure your From address matches your login, reduce message size, and consider pausing campaigns. For Amazon SES, verify all email addresses used in your mailings.
If you encounter an SMTP connection error, it’s likely due to your email service provider rejecting one of your email addresses. Ensure your “from,” “reply-to,” and “bounce” addresses match the authenticated SMTP email. Check DNS functionality and connectivity using commands like `dig` and `telnet`. If issues persist, contact your ISP for support.
Campaigns may pause or fail to send emails due to SMTP authentication errors, incorrect credentials, or blocked ports. Ensure you’re using the correct email for authentication, check your sending limits, and consider changing your delivery method. If issues persist, pause and resume your campaign later.
Integrate SendGrid with Mailster by signing up, creating an API key with specific permissions, and authenticating your sender. Choose between Domain Authentication or Single Sender Verification. Finally, test your setup by sending a test message through Mailster to ensure everything functions correctly.
Using GoDaddy’s email servers is possible but comes with restrictions. Limit your SMTP sends to 500 emails per account, ensure your from and reply-to addresses match your domain, and configure settings with the specified server details. Be mindful of additional limitations that may apply.
Mailster’s email delivery relies on your sending server’s response, but a “success” message doesn’t guarantee inbox delivery. Emails may end up in spam, bounce back, or face delays. Use Mailster’s Email Health Check to assess deliverability and consider changing delivery methods or servers if issues persist.
SparkPost is a reliable email delivery service that requires setup, including domain verification and API key creation. While it no longer offers a free tier, a “Test Account” can be used for evaluation. Users must configure DNS settings and integrate with Mailster to start sending emails effectively.
SMTP (Simple Mail Transfer Protocol) utilizes various ports (25, 993, 465, 587) for email sending, but providers may block specific ports or restrict use to their own servers. To check port accessibility, visit Settings => Newsletter => System Info. Consider alternative delivery methods or free plugins if ports are blocked.