Email Error "Error while sending email!"

Hi–

I have a sever that hosts several WordPress sites that are all using BackWPUp to automatically backup the sites. They all have two backups setup–one to backup all the files to Dropbox and one to email a SQL dump.

On one of the sites I’m getting an error message Error while sending email! when the job to backup via email runs (I also get this error when I click “send test email”). On every other site hosted on the same server the email backup runs without issue–so I do not believe it is an issue with the server configuration. Also the standard WordPress admin emails and even the BackWPUp email alert to notify me that the job failed are working fine.

So I believe there is an issue with my configuration somewhere but I can’t nail down what the problem might be.

I’d really appreciate any help. Thanks!

Job Log:

[INFO] BackWPup 3.3.3; A project of Inpsyde GmbH
[INFO] WordPress 4.5.3 on http://www.dallassportsrant.com/
[INFO] Log Level: Normal
[INFO] BackWPup job: DSR Email Backup
[INFO] Logfile is: backwpup_log_723a80_2016-07-29_03-03-40.html
[INFO] Backup file is: dsr_backup_2016-07-29_03-03-40.tar.gz
[29-Jul-2016 03:03:40] 1. Try to backup database …
[29-Jul-2016 03:03:40] Connected to database DallasSportsRant on localhost
[29-Jul-2016 03:03:40] Added database dump "DallasSportsRant.sql" with 2.65 MB to backup file list
[29-Jul-2016 03:03:40] Database backup done!
[29-Jul-2016 03:03:40] 1. Trying to create a WordPress export to XML file …
[29-Jul-2016 03:03:44] Check WP Export file …
[29-Jul-2016 03:03:44] WP Export file is a valid WXR file.
[29-Jul-2016 03:03:44] Added XML export "Dallas-Sports-Rant.wordpress.2016-07-29.xml" with 3.14 MB to backup file list.
[29-Jul-2016 03:03:45] 1. Trying to generate a file with installed plugin names …
[29-Jul-2016 03:03:45] Added plugin list file "Dallas-Sports-Rant.pluginlist.2016-07-29.txt" with 3.29 kB to backup file list.
[29-Jul-2016 03:03:45] 1. Trying to generate a manifest file …
[29-Jul-2016 03:03:45] Added manifest.json file with 6.53 kB to backup file list.
[29-Jul-2016 03:03:45] 1. Trying to create backup archive …
[29-Jul-2016 03:03:45] Compressing files as TarGz. Please be patient, this may take a moment.
[29-Jul-2016 03:03:45] Backup archive created.
[29-Jul-2016 03:03:45] Archive size is 1.33 MB.
[29-Jul-2016 03:03:45] 5 Files with 5.80 MB in Archive.
[29-Jul-2016 03:03:45] 1. Try to send backup with email …
[29-Jul-2016 03:03:45] Sending email to chris@chrisreedtech.com…
[29-Jul-2016 03:03:46] ERROR: Error while sending email!
[29-Jul-2016 03:03:46] 2. Try to send backup with email …
[29-Jul-2016 03:03:46] Sending email to chris@chrisreedtech.com…
[29-Jul-2016 03:03:47] ERROR: Error while sending email!
[29-Jul-2016 03:03:47] 3. Try to send backup with email …
[29-Jul-2016 03:03:47] Sending email to chris@chrisreedtech.com…
[29-Jul-2016 03:03:47] ERROR: Error while sending email!
[29-Jul-2016 03:03:47] ERROR: Step aborted: too many attempts!
[29-Jul-2016 03:03:47] ERROR: Job has ended with errors in 7 seconds. You must resolve the errors for correct execution.

https://wordpress.org/plugins/backwpup/