Corporate email blocking incoming ZOHO e-mail Notification

Corporate email blocking incoming ZOHO e-mail Notification

ZOHO project has e-mail notification when entries or changes are made. The ONLY e-mails that are successfully received are the ones sent to third party addresses like hotmail or Yahoo. Our corporate IT dept suggests that the problem lies with ZOHO sending the e-mails with OUR domain name as a source as opposed to Zoho.com. Our firewall is interpreting these e-mails as a "spoof" attempt. Is there a way to configure the notifications to show that they are coming from ZOHO instead of from our intranet?  Please advise as these notifications are a very important feature of us choosing ZOHO in the first place.
 
SMOKEM