I got your point .
You obviously didn't.
Thing is my customers were getting verification mail from my website.
This problem arises in last 5 days.
You probably weren't using a custom service, it was just using the built-in local emailer. Like I said earlier, it is most likely spam filters which are catching your emails, as the local emailer has no trust factor.
how can i know which custom service I was using ?
I can't possibly tell you what custom service you were using. If you never entered anything into those fields, you were never using a custom service.
Answer these questions:
- What are you trying to accomplish?
- What do you expect the Custom Service setting to do?
If you are trying to set up an email service to deliver emails for your site, you can try using Gmail. Select the Gmail service in the list, and then enter the credentials for a Gmail account in the respective fields.