topic Re: SMTP: Email is queued for delivery, but is never received. in APIs & Integrations

SMTP: Email is queued for delivery, but is never received.

TBaer — Tue, 02 Jul 2024 12:27:04 GMT

I'm using the SMTP API to send emails. When I use the Hubspot SMTP server to send an email, the email is sent, but never received anywhere (not even in spam/junk).

I've tried this both programmatically (C#) and using OpenSSL CLI in command-line on Windows. When sending an email in command-line, everything seems to work and I end up with this message:

250 2.0.0 Ok queued as 1719921339562/81cabff0-cd35-4676-9407-995b0577d003 R7q4cmPrZW4VKHXQ2zlYTr0 - hssmtp

Despite this message, the email is never received.

I'm using the Username and Password from our SMTP token, calling the smtp.hubapi.com server. I've tried both port 25 and 587 with the same result. Both the From and To addresses are addresses in my company's domain.

What can I do to diagnose this issue and make sure the email is received?

Re: SMTP: Email is queued for delivery, but is never received.

Humashankar — Tue, 02 Jul 2024 13:22:10 GMT

Hi @TBaer

When the SMTP server indicates "Queued for delivery", it confirms that it has successfully received the email from the SMTP client and will attempt to deliver it.

However, if the email ultimately fails to reach its destination, the issue lies beyond the initial handoff to the SMTP server.

In this case, you'll need to investigate the SMTP server's settings, configuration, and related factors to diagnose and resolve the problem.

Hope this helps - Happy to help further!!
Thank you very much and have a great one!
Warm regards

Re: SMTP: Email is queued for delivery, but is never received.

TBaer — Tue, 02 Jul 2024 13:55:31 GMT

Thank you for the response @Humashankar. Could you give me an idea of where I can view these settings and config? Is it something that only my company's admin user will have access to?

Re: SMTP: Email is queued for delivery, but is never received.

Humashankar — Tue, 02 Jul 2024 14:42:08 GMT

Hi @TBaer

Can you give a head start with this - Analyze the performance of a sent email with the help of this article -
Review and analyze your marketing emails (Review and analyze your marketing emails (hubspot.com), delivery logs within your HubSpot account.

Even without full admin access, these logs might show basic information about your sent emails, including potential delivery errors to start the triage by yourself.

Hope this helps.

Re: SMTP: Email is queued for delivery, but is never received.

TBaer — Tue, 02 Jul 2024 16:10:45 GMT

Thanks again for the reply @Humashankar. This email is not a marketing email, it's an email sent via SMTP, so it doesn't show up in the list of marketing emails. Do you know if there's anywhere I can configure settings for the Hubspot SMTP server? Or where I can see logs of emails that I've sent there?

Re: SMTP: Email is queued for delivery, but is never received.

Humashankar — Tue, 02 Jul 2024 16:18:52 GMT

Thank you for providing more context. You are right that emails sent through HubSpot's transactional SMTP API will not appear in the Marketing Email dashboard.

Overall, without full admin access, it is not possible to configure settings for HubSpot's internal SMTP server or access detailed logs for transactional emails

To further troubleshoot the issue, consider sending a test email to an alternative email address, ideally one that is not associated with the recipient's company domain. This will help determine if the problem is specific to the recipient's server or a more general issue.

Re: SMTP: Email is queued for delivery, but is never received.

TBaer — Tue, 02 Jul 2024 16:28:50 GMT

I've sent a test email to several other email addresses in different domains and gotten the same result, which leads me to think it's a more general issue. I will contact my admin to access the logs and settings for the SMTP server.

Re: SMTP: Email is queued for delivery, but is never received.

Humashankar — Tue, 02 Jul 2024 17:22:58 GMT

Absolutely - Thanks for the update!

Re: SMTP: Email is queued for delivery, but is never received.

TBaer — Thu, 04 Jul 2024 09:13:37 GMT

It turned out that the recipient mailboxes were blocking the mail as suspected phishing attempts. Safelisting the domain (transactional.eu1.hubspotemail.net) solved the issue.