email - logback using external properties file not working correctly -

i think hit playframework - logback specific bug, perhaps not, assistance great!

i' ve needed email appender send me emails when error occures.
created simple 1 properties defined within:

<appender name="email" class="ch.qos.logback.classic.net.smtpappender">     <smtphost>myhost</smtphost>     <smtpport>25</smtpport>     <starttls>true</starttls>     <username>username</username>     <password>pass</password>     <to>to</to>     <from>from</from>     <subject>error: %logger{20} - %m</subject>     <layout class="ch.qos.logback.classic.patternlayout">         <pattern>%date %-5level %logger{35} - %message%n</pattern>     </layout> </appender> 

this worked fine.
wanted refactor of properties cause don't want commit passwords , stuff source control.
replaced properties ${propname} , added @ begining

<property file="conf/mail.properties"/> 

now emails not sent anymore.
debugged , printed out properties , saw problem has quotes.
to/from email addresses, when put them in properties file need surround them quotes otherwise error this:

caused by: com.typesafe.config.configexception$parse: /myconfdir../mail.properties: 19: reserved character '@' not allowed outside quotes 

also password has "+" symbol in , if it's unquoted in properties file same error.
when debugging these quoted values see quote included inside them.
email trying sent "a@b.com" , no a@b.com. same field , password.
doesn't work.

any idea how prevent this?

i have done same task :

in logback.xml file, add :

property resource="filename.properties"  <username>${username}</username> <password>${password}</password> <to>${email1}</to> <from>${from}</from>