New features in outgoing email settings SharePoint 2016

Introduction of New features in outgoing email settings like non-default port can be set in the field “SMTP Server port”. which means SMTP server can use non-default ports.

SharePoint Server 2016 supports sending email to SMTP servers that use STARTTLS connection encryption.STARTTLS is an extension to plain text communication protocols, which offers a way to upgrade a plain text connection to an encrypted (TLS or SSL) connection instead of using a separate port for encrypted communication.

This Outgoing Email Settings supports sending mail to SMTP servers using STARTTLS connection encryption, therefore SMTP can use non-default ports. It does not support unencrypted connections.

The following list shows the SharePoint 2016 requirements that are needed to negotiate connection encryption with an SMTP server:

• STARTTLS must be enabled on the SMTP server.
• The SMTP server must support the TLS 1.0, TSL 1.1, or TLS 1.2 protocol.
• The SMTP server must have a server certificate installed.
• The server certificate must be valid. Typically, this means that the name of the server certificate must match the name of the SMTP server provided to SharePoint. The server certificate must also be issued by a certificate authority that is trusted by the SharePoint server.
• SharePoint must be configured to use SMTP connection encryption.

Secure Sockets Layer (SSL) with SMTP Connection Encryption

To configure SharePoint to always use SMTP connection encryption, In SharePoint Central Administration website and under System Settings , Configure outgoing e-mail settings and set the Use Secure Sockets Layer (SSL) drop-down menu to Yes. To configure SharePoint to always use SMTP connection encryption in Windows PowerShell, use the Set-SPWebApplication cmdlet without the -DisableSMTPEncryption parameter.

For example:
$WebApp = Get-SPWebApplication -IncludeCentralAdministration | ? {
$_.IsAdministrationWebApplication -eq $true }
Set-SPWebApplication -Identity $WebApp -SMTPServer smtp.internal.contoso.com -OutgoingEmailAddress sharepoint@domain.com -ReplyToEmailAddress sharepoint@domain.com

Secure Sockets Layer (SSL) with No SMTP Connection Encryption

To configure SharePoint to never use SMTP connection encryption in SharePoint Central Administration, browse to System Settings > Configure outgoing email settings and set the Use Secure Sockets Layer (SSL) drop-down menu to No.

To configure SharePoint to never use SMTP connection encryption in Windows PowerShell, use the Set-SPWebApplication cmdlet with the -DisableSMTPEncryption parameter.

For example:
$WebApp = Get-SPWebApplication -IncludeCentralAdministration | ? {
$_.IsAdministrationWebApplication -eq $true }
Set-SPWebApplication -Identity $WebApp -SMTPServer smtp.internal.contoso.com -DisableSMTPEncryption -OutgoingEmailAddress sharepoint@domain.com -ReplyToEmailAddress sharepoint@domain.com