Error while sending email through our own email library activity


We have created user defined activity to send emails. i.e., separate activity we have created and using it for sending emails.

It was working fine. But in particular machines we are getting below error. Any idea what is the issue here?

There is no issue in code.
Also we have copied all the packages from another machine (where this send email is working). That is also not working.
I cannot share the code of the activity. Please share your ideas.

Hi @vigneshnkv which mail activity your are using ? smtp or outlook mail?