Instead of using second mailer with a different configuration we just send from the PHPMailer
as it was configured in wp_mail function.
[MAILPOET-4254]
Recently we've stopped incrementing sending counter when site configured to use MSS.
This caused that also code reseting the sending error was skipped.
This commit changes incrementSentCount method so that it always clears error log.
[MAILPOET-4448]
We can't create mailer directly in DI container using the factory because it may fail in case
the plugin is not configured properly and prevent plugin from start.
The Mailer was previously injected because it contains lazy initialization.
The lazy initialization in the singleton Mailer service was dangerous,
because when used with some custom parameters it could cause that all services
that inject the Mailer from DI would use the custom config instead the default.
[MAILPOET-4115]
In this commit I copied and slightly modified functionality used
for creating Mailer instance based on config from the Mailer to an extra class.
The functionality still remains also in Mailer and will be removed later.
I also created test based on the original test for Mailer and added test case
testing it creates specific MailerMethods.
[MAILPOET-4115]
Before this commit, we used to calculate whether the sending limit was reached
by simply counting, how many emails where sent and when we did send them the
last time. In case the last time we did send was before the sending frequency,
and we reached the limit we would reset the calculation.
This led to the following problem:
In case we had e.g. one email send at an outdated timestamp, we would first fill
the outdated timestamp and once we reached the limit, we would reset the counter
and start with the current timestamp. So it followed, we would send more emails
than the limit would allow for.
[MAILPOET-4122]
