Why did my Mailgun delivered emails drop?
The Mailgun help pages give 5 common reasons. The first to rule out: If an address bounced before, Mailgun stops sending to it, so those emails are never delivered.
Is it broken, or just quiet?
A number can fall because fewer people came, or because something stopped counting them. Below are the causes the Mailgun help pages give, and how to check each one yourself.
What causes it?
If an address bounced before, Mailgun stops sending to it, so those emails are never delivered.
In the Mailgun help:
The email was suppressed due to a previous bounce with the recipient address.
Metric Definitions for Reporting, read 2026-11-12.Emails to people who unsubscribed are not sent at all, so they do not count as delivered.
In the Mailgun help:
The email was suppressed due to a previous unsubscribe from the recipient. No delivery attempt was made.
Metric Definitions for Reporting, read 2026-11-12.If someone marked an earlier email as spam, Mailgun does not try to send to them again, so fewer emails are delivered.
In the Mailgun help:
The email was suppressed due to a previous complaint from the recipient. No delivery attempt was made.
Metric Definitions for Reporting, read 2026-11-12.Some emails fail for now and Mailgun tries again later, so they can be delivered on a later day than they were sent.
In the Mailgun help:
Mailgun could not deliver the email to the recipient email server, but will retry.
Metric Definitions for Reporting, read 2026-11-12.Some emails fail for good, and Mailgun does not try them again, so they are never delivered.
In the Mailgun help:
Mailgun could not deliver the email to the recipient email server, and will drop the message without retrying sending.
Metric Definitions for Reporting, read 2026-11-12.
How do I check it myself?
Read delivered as accepted by the recipient's email server. It does not tell you whether the email reached the inbox.
In the Mailgun help:
Mailgun sent the email and it was accepted by the recipient email server.
Metric Definitions for Reporting, read 2026-11-12.Compare delivered with sent. Sent covers delivered and failed emails, but not the ones Mailgun suppressed, so check suppressed separately.
In the Mailgun help:
A count of all sent messages. This includes delivered and failed messages, but does not include suppressed messages.
Metric Definitions for Reporting, read 2026-11-12.Look at failed emails next to delivered ones. A rise in failures, temporary or permanent, explains a drop in delivered.
In the Mailgun help:
A sum of all permanent and temporary failures.
Metric Definitions for Reporting, read 2026-11-12.
How would I know the day it starts?
- Feder reads your emails delivered and your email clicks from Mailgun each day and compares each day with your own history.
- It tells you when deliveries go quiet or either number moves outside its usual range.
Some numbers are too quiet to judge daily, such as a form filled in a few times a week. Until there is enough of your own history to judge a change, Feder says it is still learning and scores nothing, rather than guessing.
See what Feder reads from Mailgun, which feeds Reach. Feder only reads. It never changes anything in Mailgun.
What else goes wrong with these numbers?
- Why do my Mailgun email clicks look wrong?Mailgun
- Why are my Mailgun email clicks not being tracked?Mailgun
- Why did Google Analytics stop collecting data?Google Analytics
- Why aren't my key events showing in Google Analytics?Google Analytics
- Why does Google Analytics show (not set)?Google Analytics
See every question.
Where do these answers come from?
Every cause and check on this page comes from the Mailgun help pages, quoted above with the date we read them. Last reviewed 2026-11-12. We read them again by 2027-11-12. If one changes, this page changes or comes down.