Only some emails are stuck in mail queue

Question

User-733996868 posted

Hi All 

I am trying to send emails from SMTP mail server with AZURE VM (WINDOWS 2012 R2).   I am using SMTP Host: localhost, PORT:25. When we send email all email recipients getting emails except few emails. I tried with Port 587 thinking that some ISPS block Port 25 but no luck.  

SMTP log says

02:04:42 xx.xxx.xxx.21 QUIT - 0. The CC and BCC used along with that email are getting emails correctly. 

What may be the issue? Why only some email receipts not getting emails. ?

Answer 1

User-271186128 posted

Hi narasappa,

Only some emails are stuck in mail queue

From your description, it seems that you are using queue to send emails, so I suppose perhaps the issue is related to the queue.

Can you tell me which kind of queue service you are using? Azure Storage Queue service or Service Bus Queue service?

If you are using Azure storage queue, please check the poison queue message:

https://docs.microsoft.com/en-us/azure/app-service-web/websites-dotnet-webjobs-sdk-storage-queues-how-to

If you are using Azure Service Bus queue, I suggest you check the Service Bus dead-letter queues:

https://docs.microsoft.com/en-us/azure/service-bus-messaging/service-bus-dead-letter-queues

Besides, if still not working, I suggest you could try to use send Email Using SendGrid with Azure:

https://docs.microsoft.com/en-us/azure/app-service-web/sendgrid-dotnet-how-to-send-email

Best regards,
Dillion