self-hosting Email error

Email shown as sent but never reached destination,

On reviewing the invoice in question there was a warning icon

View in Portal [Warning icon]
Address in mailbox given [] does not comply with RFC 2833, 3.6.2.

was sent to a @gmail.com account.
Can you provide any info.

Also the “contact us” icon in the app will not do anything if I click send.

-------- laravel-error log -------------
[2019-11-15 15:49:03] production.ERROR: Swift_RfcComplianceException [0] : /home/ninjacelutions/public_html/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Mime/Headers/MailboxHeader.php [Line 355] => Address in mailbox given [] does not comply with RFC 2822, 3.6.2. {“context”:“PHP”,“user_id”:1,“account_id”:1,“user_name”:“Cel Administrator”,“method”:“POST”,“user_agent”:“Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.97 Safari/537.36”,“locale”:“en”,“ip”:“147.147.131.255”,“count”:1,“is_console”:“no”,“is_api”:“no”,“db_server”:“mysql”,“url”:“contact_us”} []
[2019-11-15 15:49:17] production.ERROR: Swift_RfcComplianceException [0] : /home/ninjacelutions/public_html/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Mime/Headers/MailboxHeader.php [Line 355] => Address in mailbox given [] does not comply with RFC 2822, 3.6.2. {“context”:“PHP”,“user_id”:1,“account_id”:1,“user_name”:“Cel Administrator”,“method”:“POST”,“user_agent”:“Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.97 Safari/537.36”,“locale”:“en”,“ip”:“147.147.131.255”,“count”:2,“is_console”:“no”,“is_api”:“no”,“db_server”:“mysql”,“url”:“contact_us”} []
[2019-11-15 15:49:18] production.ERROR: Swift_RfcComplianceException [0] : /home/ninjacelutions/public_html/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Mime/Headers/MailboxHeader.php [Line 355] => Address in mailbox given [] does not comply with RFC 2822, 3.6.2. {“context”:“PHP”,“user_id”:1,“account_id”:1,“user_name”:“Cel Administrator”,“method”:“POST”,“user_agent”:“Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.97 Safari/537.36”,“locale”:“en”,“ip”:“147.147.131.255”,“count”:3,“is_console”:“no”,“is_api”:“no”,“db_server”:“mysql”,“url”:“contact_us”} []


App Version: v4.5.16
White Label: No - xxxxxxx
Server OS: Linux 2.6.32-896.16.1.lve1.4.54.el6.x86_64
PHP Version: 7.2.24
MySQL Version: 10.0.38-MariaDB

Actually was an error in Settings> System Settings > SMTP Email Settings