In some cases, it might be required to have detailed logging of this activity for troubleshooting such things as missed alarm notification, unexpected content inside the e-mail message or for other purposes.
Before performing the further steps, please make sure that you have configured SMTP server settings in Veeam ONE Monitor server settings (https://helpcenter.veeam.com/docs/one/deployment/notification_smtp_server.html).
This logging is disabled by default and must be enabled in the registry:
1) Log on to the machine where Veeam ONE Monitor service is installed.
Open Registry Editor and navigate to the Veeam ONE Reporter registry folder:
For both x86bit and x64bit systems: HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam ONE Monitor\Service\
2) Create the following registry key:
Name – LogSmtpActivity
Type – DWORD
Value – 1 *
3) Restart the Veeam ONE Monitor service (VeeamDCS.exe process)
After this action, all further SMTP activities will be reflected in the files named as "VeeamDCS-MailActivity-<YYYY_MM_DD_HH_MM_SS>.log" in folder %ProgramData%\Veeam\Veeam ONE Monitor\Logs. Each log file contains a full SMTP dialog between the SMTP server on sending individual e-mail, including the status codes (220, 250, etc.) and HTML markup of the subjected e-mail.
Each log has the following format (an example):
Connected to smtp://smtprelay.contonso.com:25/ S: 220 smtprelay.contonso.com ESMTP Postfix C: EHLO [192.168.0.1] S: 250-smtprelay.contonso.com S: 250-PIPELINING S: 250-SIZE 36700160 S: 250-ETRN S: 250-STARTTLS S: 250-ENHANCEDSTATUSCODES S: 250-8BITMIME S: 250 DSN C: MAIL FROM:<VeeamOneServerMachine@contonso.com> SIZE=364 C: RCPT TO:<email@example.com> S: 250 2.1.0 Ok S: 250 2.1.5 Ok C: DATA S: 354 End data with <CR><LF>.<CR><LF> C: From: VeeamOneServerMachine@contonso.com C: Date: Tue, 11 Feb 2020 13:35:53 +0300 C: Subject: Veeam ONE Monitor C: Message-Id: <WB128P30U9U4.IS9J8ZHC935G3@VeeamOneServerMachine> C: To: firstname.lastname@example.org C: MIME-Version: 1.0 C: Content-Type: text/html; charset=utf-8 C: Content-Id: <HNT78P30U9U4.094QYWZZHYV63@VeeamOneServerMachine> C: C: This is test e-mail message sent by Veeam ONE Monitor. C: . S: 250 2.0.0 Ok: queued as 804B240A1D C: QUIT S: 221 2.0.0 Bye