Zoho Mail - Delay receiving e-mails on Gmail accounts

Zoho Mail - Delay receiving e-mails on Gmail accounts

Hi, I am developing a website that uses Zoho Mail SMTP. It is used to send informative e-mails to the users and e-mails with links to verify the accounts and/or to reset passwords. But I noticed that some e-mails were being sent with a 4/5min delay. I started testing with 2 Gmail accounts and 2 Outlook accounts and realized the e-mails are sent in time to the Outlook accounts and the delay only happens on the Gmail accounts. For example, if the API sends an e-mail with a verification link at 10:00 AM, the Gmail account will only receive it at 10:05 AM. However, the time shown in the e-mail, when it is received, is 10:00 AM. Any thoughts on this?