Mail Forwarding for new domain slow

Mail Forwarding for new domain slow

I just moved my email services over to Zoho earlier this afternoon (domain.com), and set my MX records to start delivering my mail to Zoho.    I have all of my various email addresses dumping into one central gmail account - so I have taken one of my Zoho names, and set it to store and forward all messages over to my gmail.    My old MX record had a 1 week TTL, so it looks like some mail servers are already seeing zoho, and some are not.  No big deal to me on that front, they'll update MX eventually.

I've noticed that when sending an email from my work email to my domain.com email, zoho's inbox shows it almost immediately (< 1min).   However, it's not received in gmail until 4-6 minutes later.   This seems consistently the time frame over my tests today.

If I send an email from Zoho directly to my gmail, it's also almost immediately delivered.

Is zoho's mail forwarding service a little slow to react? 

Thanks,