Unable to use variables in "Send an email" step

I created variable called ProjectApproverEmail and then used the variable in the To field. When the step runs, I get following error.

Fatal 09:57:52
The specified string is not in the form required for an e-mail address.
System.FormatException: The specified string is not in the form required for an e-mail address.
at System.Net.Mail.MailAddressParser.ReadCfwsAndThrowIfIncomplete(String data, Int32 index)
at System.Net.Mail.MailAddressParser.ParseAddress(String data, Boolean expectMultipleAddresses, Int32& index)
at System.Net.Mail.MailAddressParser.ParseMultipleAddresses(String data)
at System.Net.Mail.MailAddressCollection.ParseValue(String addresses)
at Octopus.Server.Orchestration.Deploy.Email.EmailActionOrchestrator.CreateMessage(SmtpConfiguration smtp, DeploymentAction action, IDeploymentManifest manifest) in y:\work\refs\heads\master\source\Octopus.Server\Orchestration\Deploy\Email\EmailActionOrchestrator.cs:line 92
at Octopus.Server.Orchestration.Deploy.Email.EmailActionOrchestrator.d__0.MoveNext() in y:\work\refs\heads\master\source\Octopus.Server\Orchestration\Deploy\Email\EmailActionOrchestrator.cs:line 48
Octopus.Server version


Thanks for reaching out. Could you please enable these debugging variables on your project, then create a new release (so the variables take effect), deploy it and send us the raw log? If possible, try to run as fewer steps as possible to avoid extra noise in the logs. This should help us know what is going on with the email.