We are building a rails application that's sort of a CRM + room/course
booking. Among other things, it provides a centralized database of all
the people the company has been in contact with.
We want to provide the possibility of sending customized email messages
to groups of contacts, for example a newsletter to 500 people starting
with "Hi [:name:]". The naive approach we're using is basically placing
the following code in the controller:
email.people.each do |p|
# This generates a custom email for that person, with fields such as
[:name:]
# filled with the person's name
raw_email = PeopleMailer.create_general_email(email, p, sent_at)
raw_email.set_content_type("text/html")
begin
PeopleMailer.deliver(raw_email)
rescue Exception => e
email.log += "\n" + format_time(Time.now) + "\n" + e.message + "\n"
end
end
The problem is that generating the 500 individual emails takes a
significant amount of time, which causes the browser to time out. What
we want, is to give the user a response immidiately, and then process
the sending of the email in the background.
let me know what you find, as I'm doing the same thing right now (with
about 200 users, and I'm doing it the naive way, which works, but I've
been wanting to transition to a background process as well).
I don't know about running processes in the background, since our
mailing list goes out from a cron job, but we do individualize emails,
mainly for the point of putting in an "Unsubscribe" link for each user.
Also, we found it was best to send the emails in slices of 50. That way
the SMTP Session doesn't get way too big, but it cuts way down on
sending time. Not sure if it's on the script side or the email server
that slows it down(I think it's the email server because it's not
caching the emails but I guess either way they have to sit around for a
short while), but this sends about 6 emails/second. For 500 emails,
that's...just under a minute and a half.
Here's the code:
This is in our main method in the model, Emailer.send_daily_announcements
@users.each_slice(50) do |recipient_group|
# Create an SMTP connection for this group of users
Net::SMTP.start('smtp.server.here', 25) do |smtp|
# Send the email to each user in this group
for recipient in recipient_group
begin
# Output each recipient - TESTING ONLY
puts "Sending email to: #{recipient.email}"
# Create the email message from our template
email = Emailer.create_daily_announcement(recipient,
@other_variables)
# Send out each email
smtp.sendmail email.encoded, email.from, email.to
rescue Exception => e
exceptions[recipient] = e
logger.warn("EXCEPTION: EMAILER.ANNOUNCEMENTS:" + e)
puts e
smtp.finish
smtp.start
end
end
end
end