I've been testing a new campaign created via the API with a small subset of recipients. All 3 recipients with gmail (including myself) report they don't receive the campaign email. All other recipients experience no problems. I do not believe the API itself is the issue; the result is the same regardless of whether I send the campaign via the API or via Campaign Monitor's dashboard.
Campaign Monitor reports the campaign sent and shows zero bounces. Gmail shows no trace of the message for any of the recipients - not in spam/trash, not locatable by search, nada.
It's been roughly two hours since the campaign was sent, and the gmail accounts have received other emails in the interim so I don't *think* it's an issue of the campaign being held up in a big queue on that end.
With no feedback or error message on either the Campaign Monitor end or the Gmail end, I'm at a loss how to debug the problem. Any suggestions?
EDIT: Never mind, finally went. Looking at the headers there's just a several-hour gap between when campaign monitor's SMTP gets the email and when Gmail's SMTP finally receives it.
Hi gohanman, welcome to the forums - we're really glad that the email got through and sorry for the delay there. We've noticed in recent weeks that while we've been sending from our mail servers on-time, Gmail has been delaying the delivery of email on their end, usually by 2-3 hours. This is a very rare, intermittent behaviour that's affected only a few of our customers, so we're sorry to hear that you were caught out in this instance.
We're currently in the process of warming up additional sending IPs to make this a far less-common occurrence, but please let us know if you come across Gmail-specific delays again. Sorry again for the wait here, it's understandably a frustrating thing to happen.