Mail sended with workflow takes a long time (Office 365 - E3)

Dear,

I have made a workflow that sends an email when an item is checked.

The workflow does some tests and is completed in less then 1 minute. But the mail which is generated in that workflow take hours before it is received.

Anyone know how I can fix this?

For example yesterday evening workflow completed at 16:58 and I received the mail at 18:52.

Thanks in advance!

WKR

Grim