Knowledgebase: Pegasus Opera
Emailing Payslips or P60s from Opera3 Failing and when doing test email error Failure sending mail: unable to read data from the transport connection: net_io_connectionclosed
Posted by Claire Craig, Last modified by Claire Craig on 16/05/22 15:26

If a problem starts to occur when emailing payslips or P60's from Opera3 where they FAIL

Run a TEST email from the Pegasus Scheduler Set Options, if you get:

Failure sending mail: unable to read data from the transport connection: net_io_connectionclosed

and the Email Server Settings are similar to the below with additional authentication, the issue will be related to TLS1.0/TLS1.1 being disabled by Microsoft for that 0365 Tenant (which Microsoft are rolling out without any warning)

To remedy, firstly try forcing the TLS version to 2.0 in the registry (supplied by Steven McGroggan)

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

Further description from Pegasus with regards to how Pegasus Scheduler determines the TLS to use:

When the "Tick to use SSL connection" in Scheduler is selected, it covers both SSL and TLS. 

Scheduler uses a version of the .NET framework that will automatically select the best TLS version possible. This will be the highest version common between the Scheduler Server and the SMTP server machines.

The default versions on a machine are dependent on the operating system but can be further restricted via the registry. Windows Server 2016 and later supports TLS 1.2 by default.

It is possible for other hardware or software to block TLS 1.2, such as a firewall or other network security software.

OR if this is unsuccessful, then the below may be the only option.......

follow the instructions on below link on "New opt-in endpoint available for SMTP AUTH clients still needing legacy TLS"

https://techcommunity.microsoft.com/t5/exchange-team-blog/new-opt-in-endpoint-available-for-smtp-auth-clients-still/ba-p/2659652

New SMTP details are then needed input into Opera3

(the lead engineer which fixed this for another customer was Robert McKibben if you have any queries)

(0 vote(s))
Helpful
Not helpful

Comments (0)