After installed Mailer plugin version 1.13. I can not sending email to individuals who broke the build.
ERROR: Unable to send to address: email@example.com,firstname.lastname@example.org
javax.mail.internet.AddressException: Illegal address in string ``email@example.com,firstname.lastname@example.org''
Problem is probably that there is inserted a comma instead of a space.
After downgrading the old version 1.12 it works.
Thank you for your the fix