SSIS send mail task error (once smtp server changed)

Hello All,

i have a ssis package, which is running fine so far, if it fails it notify to tech support team,
SMTP server Name got changed so i updated new name, i didn't touch anything else, but when the package fails it is not getting notified also it throws below message (when i ran in ssis bids)


SSIS package "CitiFeedGrabber.dtsx" starting.
Error: 0xC002F304 at Notify Support Team Send Mail Task, Send Mail Task: An error occurred with the following error message: "Failure sending mail.  System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed.".
Task failed: Notify Support Team Send Mail Task


do i need to configure anything, am i doing anything wrong?

please help me

Thank you so much in advance

best regards
asita