Hello,
I configured split delivery, being Google the main server, where the MX records point to. I configured 2 different DKIM records in my DNS provider, 1 for Google and 1 for Zoho. I verified in
https://mxtoolbox.com that both records are valid.
Mails sent from the accounts in Gmail don't have any problem, but mails from Zoho accounts sometimes fail to deliver, and when sent to a Gmail account, the recipient gets the message "Gmail couldn't verify that Domain actually sent this message...". When I go to the option "Show Original" it shows:
SPF: NEUTRAL with IP ...
DKIM: FAIL with domain ...