Unable to send email: Timeout Error

[YaminV]

Hi everyone, 

I have a workflow which creates excel outputs then grabs each file and attaches them to an email to send to multiple people in multiple emails. The workflow works fine when sending one email on its own to 3 people, however when i try to send multiple emails with more than 3 people in some emails at the same time, i receive the below error message.

Does anyone have any ideas why this could be happening?

Thanks