We have an internal message board. If a user posts a note then all other users that have access to the thread are sent an email alert. So if there are 20 users on a thread then you could see bursts of 100s of emails over only a couple minutes.
Currently the email alerts are sent with the PHP mail() function. One time we got some local relay alerts and I think our server IP was blacklisted for a short period of time. And I think these negative consequences happened because of an email alert burst that uses mail().
Is the solution simply to use anything other than mail(), or is there more to it? How can I reproduce/test the local relays and blacklisting so that I am sure the issue is solved?
If you're sending large amounts of email the best thing you can do is use a third party email provider. There are several that offer API/SMTP services and will not be blacklisted because they work on a reputation system. Most offer composer packages you can drop in and configure relatively quickly.
SendGrid / sendgrid-api - We use this to send around 2 million emails a month without issue.
Mailgun / mailgun-php
Mandrill / mandrill-api-php
Each have their pros and cons and some offer free emails to a certain limit.
If this isn't an option you should create a dedicated email server that has all the correct DKIM/SPF records that over time will become reputable over time however it'll still slow down when you're sending many emails as it'll be limited to 1 email at a time and if it encounters a slow connection it can take a while to complete. If email is important a third party provider is definitely the best way to go.
Related
I know that for large amount of emails it is recommended to use Pear but I'm wondering if it is worth digging into it in my case (I installed it but I have many errors coming from PEAR)
I need to send emails to my subscribers (around 20K) but my host only allow 200 emails per hour. This is OK because I don't need everyone to get the e-mail at the same time, I can send all these mails within a month, I'm not in the hurry.
In that case, would it be OK to have a really simple loop that send on email with mail() and then sleep for 18 seconds (to be under 200emails/hour) . Basically, what I'm thinking is simply to do something like this
for($i=0;$i<=count($recipient);$i++)
{
mail($recipient[$i].....);
sleep(18);
}
Is this OK vs using PEAR (which require many more time) ?
Have you looked at using PEAR's Mail_Queue package? http://pear.php.net/package/Mail_Queue ? You can set it to send X many emails in one process and then rerun the same script to send the next X many.
I certainly wouldn't use the native mail function for sending anything more than concise emails, perhaps for notifying you of exceptional conditions in an app.
If your server is linux based, you might get away with that (See this question).
Although this doesn't really sound like a great solution, also taking into account that it seems like you are using a for loop with all your recipients (20k).
If you don't want to use PEAR you might want to try setting up a cron job every hour that somehow (using a text file, or a database) remembers the last user it sent an email to, and sends the next batch of 200.
In that case you might want to setup the cronjon every 125 minutes just to be sure you don't reach the limit. Also using sleep(1); after each mail() will spare CPU.
Check out this question for performance considerations.
First, I wouldn't say that the limitations of good old mail()...
Manual encoding of almost everything
Poor error handling
No authentication (though not an issue for you)
... are related to volume.
Second, I've never used PEAR Mail so I can't speak about its performance or overhead but your use case comes precisely from a low-capacity e-mail server. You don't need high performance to do things slowly, do you?
So I'd dare say you're using the wrong criteria to evaluate tools.
My advice is that you leave mail() for extremely simple and unimportant tasks (and subscriber communication does not qualify as such) and use a proper third-party mail library, not necessarily PEAR's.
Particularly, Swift Mailer features Throttler Plugin that's designed to do exactly what you ask for:
If your SMTP server has restrictions in place to limit the rate at
which you send emails, then your code will need to be aware of this
rate-limiting. The Throttler plugin makes Swift Mailer run at a
rate-limited speed.
Many shared hosts don't open their SMTP servers as a free-for-all.
Usually they have policies in place (probably to discourage spammers)
that only allow you to send a fixed number of emails per-hour/day.
The Throttler plugin supports two modes of rate-limiting and with
each, you will need to do that math to figure out the values you want.
The plugin can limit based on the number of emails per minute, or the
number of bytes-transferred per-minute.
I have an issue. I have situation where I need to send around 3000 emails per request using SMTP. However, only 30-40 reaches destination.
Do you have any idea what can be a problem and how to solve it. as server side script I am using PHP.
How the big e-mail service providers (Constant Contact, WhatCounts, etc.) do mass e-mails is to put the "campaign" in a queue and send it at a later time. They have dedicated, high-performance delivery software for looking through the queue for new campaigns to send and then send them out at rates exceeding 50,000 messages per minute. Anything you might do in PHP won't even compare.
If you are trying to send from your local computer, that won't work. DNSRBL lookups will identify your computer as being on a "DUN" (Dial-Up Network) and will block the message. Most PHP scripts also have a timeout of 30 seconds in a web server environment but running via cron a PHP script can run as long as it needs to.
You shouldn't send mass e-mails from your main e-mail server either. That's a nice, fast way to get on global blacklists so that you can't send regular e-mail to common hosts (e.g. Hotmail, GMail, etc). The big e-mail service providers have dedicated staff whose job it is to remove themselves from global blacklists. That's a full time job. You are better off paying for the service (don't forget to set up SPF records correctly if you do go this route).
Warnings and advice aside, to answer the question, use a cron job for your PHP script and put the e-mails to be sent out in a queue.
If your looking to inboxing as many emails as possible and you are not sending spam, and prefer to use your own smtp, check them out.
I am creating a system, where a list of thousands of emails will be sent periodically, I know that the mail() function in PHP is quite heavy, specially if calling it too many times simultaneously.
Roughly the way my system works , is that I create queue of emails in MySQL and send them in batches of 25 using mail(), removing from the table the top 25 sent. And I wait 2 seconds between each set of 25.
Is this too much effort for the server or I can push it a bit further?
Lets say 50 per second? Or there is a better way of sending many emails in less time without sacrificing Server performance.
I have a dedicated server without any mail() call limit.
There are other factors to consider besides performance, but the short answer is: there are better options. Amazon SES and MailChimp are the two I know about have heard positive feedback on.
Look at j08691's answer regarding the performance, but other issues with using mail() for this purpose include:
Scalability (you will hit a wall that no SMTP server can handle eventually, and you're already thinking about it)
Integrity - You are much more likely to get flagged as spammy when rolling your own mass mailer, especially using mail as it uses the local sendmail by design.
Cost/Benefit and ROI - the reliable mass-mailers get it right and for a competitive rate. At some point you are paying yourself less per hour to maintain your mail server when it crashes, getting off of black lists, writing the email layout by hand, general upkeep, etc etc than you would paying for the mass mailer service.
Overall, the big issue is that you have to do all the work yourself and you're likely to get flagged as SPAM for the benefit of not paying for a service that will be able to send hundreds of emails a second versus a hundred a minute when PHP isn't busy doing everything else it handles for your web app.
Personal anecdote (not an endorsement for SES, just mass-mailers) : We had a client that sent 100k+ emails per campaign, with 1 - 3 campaigns per day minimum. They started complaining that the clients were getting emails about "daily deals" 2 days late. It wasn't because the Mailer library was slow (even this app avoided using plain mail), it was that it couldn't be sure to send all of the emails for every campaign before the email was irrelevant. We switched them over to SES (with some optimizing on our end, but not much), and they could clear a campaign in under an hour.
From the PHP manual:
Note:
It is worth noting that the mail() function is not suitable for larger
volumes of email in a loop. This function opens and closes an SMTP
socket for each email, which is not very efficient.
For the sending of large amounts of email, see the » PEAR::Mail, and »
PEAR::Mail_Queue packages.
Try using PHPMailer. i used it to send about 100 mails everyday without any problem
I have a large board with 1 million+ members and I'm experiencing great lag between the sending of emails to each member. At the current rate it would literally take me 3 months to send emails to all 1 million members.
My machine (dedicated):
dual quad xeon
32 gigs of ram
Centos 5.4
vBulletin
I've tried configuring it a number of ways and it is still slow.
The resolution is done locally, so I don't think that's the issue. Any suggestions?
vBulletin shows as it sends out the emails (500 at a time) so I know the script isn't timing out or a memory issue. To complete a page of 500, it takes 10 minutes. I am using PHP's mail() function, which is the only other option I have other than SMTP. With previous servers I have not configured myself, it had always been fast. Now trying it with sendmail (PHP's mail function) it is so slow.
Check your /etc/hosts file.
If you have an entry for your external IP address that points to your local hostname for example:
75.23.123.21 my-server-hostname
Change it to:
127.0.0.1 my-server-hostname
Then try running the PHP mail() function again.
I'm going to say if you have 1 million subscribers you need to reach, perhaps it's better that you not do yourself. Instead, why not use a service like Mailchimp who's primary focus is on delivering email.
Think about the advantages:
You don't worry about bandwidth, infrastructure and maintenance.
You get comprehensive analytics on how your email campaigns are performing and the health of your list - you say you have a million emails but how many of them bounce back? How many are opened? what is the open rate per country?, how many are marked as spam etc?
Depending on what your business is, you can A/B test your campaigns and optimize reads/clicks/conversions.
You will obviously pay extra for this service which is separate from your current hosting costs, but with Mailchimp you pay for what you use. Also if you can reach a million humans, you probably figured out how to monetize it (if not, you really should). So using a 3rd party service might pay for itself.
Mailchimp is one of many services out there (I mention it because I use it and very happy with it). You might want to check out SendGrid, Campaign Monitor and Aweber and weigh your pros and cons.
Probably not the answer you were expecting, but this is just my $0.02.
P.S: Mailchimp also gives you an API so you can seamlessly integrate your app with their services.
From the PHP Manual
It is worth noting that the mail() function is not suitable for larger volumes of email in a loop. This function opens and closes an SMTP socket for each email, which is not very efficient.
For the sending of large amounts of email, see the » PEAR::Mail, and » PEAR::Mail_Queue packages.
I'm far from an expert, but the mail() function uses a lot more CPU and memory than normal web functions but having 1 million users may already have a significant load (CPU and IO) on your server already. This may impact the speed of sending out emails, especially if you're on an older Xeon.
From what I know, dual quad Xeons are relatively new and sending those emails shouldn't take anywhere near as long as it is.
From what I've read, a lower end single cpu dedicated server should be able to send out about 500-700 emails per minute... but that is a system dedicated to only sending emails. On a mid range server like I suspect you have I'd expect it to be able to send the emails in hours, not months.
It may be a configuration or a load issue which could be on many different levels.
so i have a couple of sites on paid shared hosting, my host limits the mail to 300 per hour.
One of my sites has more than 500 subscribers.
My question is how can i send the newsletter to all my subscribers? is there a way or a script that i can use to send the first 300 users the email and after an hour to send the rest...?
i've also considered making a gmail account to send the newsletters via smtp. Do you guys know the limit of free gmail smtp?
You shouldn't circumvent the restrictions placed by your host. I would suggest you pace your sends, and record your last-sent-id, picking up from there in your next hour. That, or you can place sufficiently sleep-time between sends to allow the entire thing to go out at a rate of about 300/hr.
Thank You for all your Reply guys... it really helped me find a solution for this inconvenience. I personally can't afford VPS hosting nor pay extra for an external for a mail server...
Considering Jonathan Solution and William's Comments i ended up developing a small php application based on XML to send different batch to 250 recipients each with a GAP of 65 minutes.
So the way it works, by default it only enables the first batch link to be clicked and send the newsletters to the first batch of users and recording the exact time this was sent in a XML file.
Then using the XML file info the next link registers that the batch before it was sent and starts a count down of 65 minutes with the time on the XML as reference.
So a Script will not be running for hours and the browser could be safely close since all the info required is in the XML file.
This may sound Simple but is a complex and efficient app that dynamically adapts to growth (new subscribers) as it queries the master Table on a database using the sql LIMIT clause to make the different batches. So it doesn't required maintenance.
If anyone is interested on the source code feel free to contact me # admin#thechozenfew.net
Google Mail does have limits, see:
Sending limits In an effort to fight
spam and prevent abuse, Google will
temporarily disable your account if
you send messages to more than 500
recipients or if you send a large
number of undeliverable messages. If
you use a POP or IMAP client
(Microsoft Outlook or Apple Mail,
e.g.), you may only send a message to
100 people at a time. Your account
should be re-enabled within 24 hours.
Source: http://mail.google.com/support/bin/answer.py?hl=en&answer=22839
To get around the problem, you could create a queue table in your db with a list of all the users you're sending the newsletter to. Then send e-mails out in bulks (500 example). Remove the e-mails from the queue table as they're sent out. You could use a cron (if on linux and host allows) to run a PHP script every hour that sends e-mails based off the queue.
I'd seek a place just to park your MX (not sure of Google's limits, but that could be a start). Its very common for mailing list managers to queue mails to fit within sending limits. I.e. a cron job queries a database, picks up 250 emails to send and sends them out.
The problem lies when you have 10,000 subscribers and need to send non-automated emails from the same MX. I.e., if your limit is consumed getting out a newsletter, what happens to your ability to reply to your own e-mail?
A lot of companies offer MX only hosting, I'd go with one of them and move the whole business of sending the list over there. Or, just get yourself a VPS (its going to be about the same monthly price).