I can't send email from ZohoCRM

I can't send email from ZohoCRM

I'm setting up our company's ZohoCRM account and am having trouble sending email to contacts/leads from within the CRM. 

I tested it a few days ago and was able to send a few messages. After adding IMAP so that I could sync my work gmail account, I started getting an error when I hit send. 

The IMAP syncing is working, as I can see all emails I've sent or received in gmail in the CRM, I just can't send emails from the CRM. 

Any suggestions on how to solve this problem?