Hi @Bannubabu Pingili ,
What's the version of your Exchange server, Exchange Online or on-premise version of Exchange?
For the particular person, is she a member of the distribution list?
Did she receive any NDR message after failing to send a mail to others?
Would you please clarify a bit more about your last comment(they are receiving as held message...)? You could share some screenshot after removing any personal information involved for elaboration.
Besides, if you are using Exchange Online, please perform a message trace and see if there's any clues about the issue.
Supposing you are running Exchange on-premise, it's suggested to have a look at the Delivery report via EAC. You run the get-messagetrackinglog cmdlet and share the output here after obfuscating private data like email address or domain name:
Get-TransportService | Get-MessageTrackingLog -MessageSubject <subject> -Sender <mailbox address> |select timestamp,EventID, Source,ConnectorID |sort-object Timestamp
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.