Unable to send email using "SMTP Authentication Support" module
18559
Unable to send e-mail. Contact the site administrator if the problem persists
34069
Why am I getting authentication errors for packages from an Ubuntu repository?
17912
Email SMTP validator
64167
Testing SMTP server is running via C#
70108
Failed to send HTML mails using PHP mail()
69404
Reverse DNS - how to correctly configure for SMTP delivery
64679
Is SMTP server required to send mail through web server, by using JavaMail API?
44330
Journey Builder: Email Send Error
85691
why i am getting The EXECUTE permission was denied on the object 'sp_send_dbmail', database 'msdb', schema 'dbo'
121302
Using JavaMail with TLS
125768
"Share with" e-mail invitations not being sent even though all other e-mails work in On-Premise SP 2013
48901
"The remote certificate is invalid according to the validation procedure." using Gmail SMTP server
34014
How to send email to multiple recipients using python smtplib?
126204
Sending mail without installing an SMTP server
147172
Javascript IMAP and SMTP client?
142306
Sending Email using java program
44692
Sendmail: DSN: Service unavailable