При отправке дефолтной функцией php, получаю ответ true, писимо не приходит, если заглянуть в /var/log/exim4/mainlog:
2017-04-03 14:13:10 [15357] cwd=/var/www/***/data/www/*** 5 args: /usr/sbin/sendmail -t -i -f ***@gmail.com
2017-04-03 14:13:10 [15357] 1cuyz0-0003zh-NW <= ***@gmail.com U=*** P=local S=401 T="My subject" from <***@gmail.com> for ***@gmail.com
2017-04-03 14:13:10 [15360] cwd=/var/spool/exim4 3 args: /usr/sbin/exim4 -Mc 1cuyz0-0003zh-NW
2017-04-03 14:13:11 [15360] 1cuyz0-0003zh-NW ** ***@gmail.com F=<***@gmail.com> P=<***@gmail.com> R=dnslookup T=remote_smtp: SMTP error from remote mail server after end of data: host gmail-smtp-in.l.google.com [173.194.220.26]: 550-5.7.1 [46.254.16.114] The IP address sending this message does not have a\n550-5.7.1 PTR record setup. As a policy, Gmail does not accept messages from\n550-5.7.1 IPs with missing PTR records. Please visit\n550-5.7.1 https://support.google.com/mail/answer/81126#authentication for more\n550 5.7.1 information. s128si7374919lja.20 - gsmtp
2017-04-03 14:13:11 [15363] cwd=/var/spool/exim4 7 args: /usr/sbin/exim4 -t -oem -oi -f <> -E1cuyz0-0003zh-NW
2017-04-03 14:13:11 [15363] 1cuyz1-0003zn-DV <= <> R=1cuyz0-0003zh-NW U=Debian-exim P=local S=1678 T="Mail delivery failed: returning message to sender" from <> for ***@gmail.com
2017-04-03 14:13:11 [15365] cwd=/var/spool/exim4 3 args: /usr/sbin/exim4 -Mc 1cuyz1-0003zn-DV
2017-04-03 14:13:11 [15360] 1cuyz0-0003zh-NW Completed QT=1s
2017-04-03 14:13:11 [15365] 1cuyz1-0003zn-DV ** ***@gmail.com F=<> P=<> R=dnslookup T=remote_smtp: SMTP error from remote mail server after end of data: host gmail-smtp-in.l.google.com [64.233.162.26]: 550-5.7.1 [46.254.16.114] The IP address sending this message does not have a\n550-5.7.1 PTR record setup. As a policy, Gmail does not accept messages from\n550-5.7.1 IPs with missing PTR records. Please visit\n550-5.7.1 https://support.google.com/mail/answer/81126#authentication for more\n550 5.7.1 information. g33si7360202lji.110 - gsmtp
2017-04-03 14:13:11 [15365] 1cuyz1-0003zn-DV Frozen (delivery error message)