An email waits in the Outbox until your provider's server accepts it. BlueMail keeps retrying on its own, and if it cannot get the message away it moves it to Drafts, complete and ready to resend and marked as a failed send (more on the mechanics in What is Outbox Folder?). A message that sits in the Outbox through several attempts is not stuck for no reason. The server is rejecting it, and the first step is to find out why.
The Email Never Reached the Outbox
If you tapped send and the message is nowhere in the Outbox, nothing has necessarily gone wrong — the Outbox only holds mail that is still waiting. Check these three in order:
- Sent. The usual answer. A send that succeeds passes through the Outbox in seconds, so you will rarely catch it sitting there. See Sent folder.
- Drafts. Where BlueMail puts a message it could not get away after retrying, complete and ready to resend. See Drafts.
- Still inside the undo window. If you set an undo buffer, BlueMail holds the message for that many seconds before sending it at all, and it is not in the Outbox during that time. The buffer is off unless you turned it on, under Settings | Global Settings | Advanced Features | Undo Send Buffer. See Undo Send.
Everything below is about a message that is in the Outbox and staying there.
Step 1: look at the error
- Tap your account avatar at the top left and open the Outbox folder (navigating between folders).
- A message that failed shows a send failure state. Open it to see the error the server returned.
- Look the error up in SMTP error codes. Each code says what the server objected to.
If There Is No Error At All
An email that shows Sending… and never moves on has not been rejected. It has not been accepted either — the send is still open, so there is no error to look up and nothing above about error codes applies yet.
That state almost always means the connection went away mid-send: BlueMail got as far as contacting the server and is now waiting to retry. Check you are actually online, and if you have switched between Wi-Fi and mobile data, see Phone Disconnects While Sending.
If it still has not moved after a few minutes and several retries, the send is being refused rather than delayed, and it will turn into a Send failure carrying an error you can look up — continue with the steps above.
The usual cause: attachments too large
If the stuck email carries attachments, size is the first suspect. BlueMail itself sets no attachment limit, and almost every provider caps the size of a single email, typically 10 to 25MB, and rejects anything bigger (SMTP errors 523 and 552 are both size rejections). Two things make this easy to hit:
- The limit applies to the whole email, not just the files, and email encoding inflates attachments by roughly a third in transit, so two 10MB files can already exceed a 25MB cap.
- The cap is enforced by the server, so nothing you change on your device helps. It fails on every retry until the attachments shrink.
What to do: remove or compress the attachments and resend, split the files across separate emails, or share big files as a link (Google Drive, Dropbox, OneDrive) instead of an attachment. BlueMail can shrink images for you as you send; see compressing images.
Other causes worth a minute
- Connection dropped mid-send. Switching between Wi-Fi and mobile data and letting BlueMail retry often clears it. See Phone Disconnects While Sending.
- The server is refusing your sign-in or settings. If every email fails, not just the big one, check the account's outgoing server settings.
