set my_pass="mypass"
set my_user="gmailusername"
set from="My Name <gmailusername@gmail.com>"
set realname = 'My Name'
set from = "gmailusername@gmail.com"
set use_from = yes
set imap_user = "gmailusername@gmail.com"
set imap_pass = "mypass"
set smtp_url="smtp://$my_user@smtp.gmail.com:587"
set ssl_force_tls = yes
set ssl_starttls = yes

Running newaliases
newaliases: warning: valid_hostname: misplaced delimiter: hpEnvy15..name
newaliases: fatal: file /etc/postfix/main.cf: parameter myhostname: bad parameter value: hpEnvy15..name
dpkg: error processing package postfix (--configure):
 subprocess installed post-installation script returned error exit status 75
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Errors were encountered while processing:
 postfix
E: Sub-process /usr/bin/dpkg returned an error code (1)