Email notifications are not being sent to certain group members

[Navaneeth1]

Certain group members have an outdated email address on the dev instance. We moved the groups, and user_has_roles XML files from dev instance to testing. The same user accounts exist in both dev instance and testing instance however, the testing instance has the latest email addresses of all users. These same users are now part of the groups that were moved but has the latest emails when we open the user forms.
The users who have different emails in dev and testing env are not receiving any emails that are part of their groups, the system tried to send it to their old email addresses even their user info has the new address. But the members of the group that has the same email addresses on both instances are recieving the emails. 

I checked each memeber in the groups on the testing instance and their email is correct. I moved the groups, group roles, and user_has_roles from dev to testing. Can someone please let me know what could've went wrong or if anyone has went through something similar?

Thank you!

[Sonam_Tiwari]

Have you checked if notification field on the user record is set to enabled for those users?

[Navaneeth1]

@Sonam_Tiwari,

That is enabled and they are receiving the email if we assign the ticket to them or they're the caller. They just don't get as part of the group.

[Sonam_Tiwari]

In the email logs, can you see the notifications being triggered to group email? Also, are these user email addresses part of the group email?

[Navaneeth1]

Yes, in the email logs the emails are getting sent to some users whose email addresses are the same on both instances. These user's email addresses are part of the group email but they have different addresses on both dev instance and testing instance. Do you think the old email addresses can somehow be copied when groups are moved by XML files?