Sending emails through SMTP and testing

Question

Hi,

I've got a PHP app with an invitation system where users can invite other users to try the service. Internally we use google apps for our domain to send/receive emails (mydomain.com).

1) My question is, can I send emails from my server with the from address being [email protected]? I am worried about the emails being blocked/ignored by the destination server. I am aware that it is possible to send the emails by configuring my php installation to use google smtp server, but there is a limit of 500 emails a day, which is not very scalable.

I don't really know that much about sending emails and why/how they are blocked/considered spam. I'd appreciate any good advice/tips you can give me.

2) What is a good way to test to see if the email portion of my app is working without installing it on my live server. Can I just setup an smtp server on my desktop and send mails this way? Can you recommend any other good ideas for testing. I'll basically be sending just a few emails to my personal webmail accounts to make sure that everything works.

Thanks, Bill

Answer 1

To address the second part (as Eric pointed out, you'll have better luck at serverfault.com with the first part), any locally hosted SMTP server should be able to do the trick, and there are plenty available for any given OS. Google can help you there.

The main thing you'll want from a local SMTP server is detailed logging. It's entirely possible that the local server could fail/refuse to deliver the message to its intended destination for any number of reasons (again, serverfault.com), but that's outside the scope of testing the code's delivery of the email to the SMTP server.

If it does properly forward the test message to you, great. But if it doesn't, you just want to be able to see in the server's logs that it received the message correctly and was able to process it. Whatever that processing accomplished is a separate issue.

Answer 2

1) My question is, can I send emails from my server with the from address being [email protected]? I am worried about the emails being blocked/ignored by the destination server. I am aware that it is possible to send the emails by configuring my php installation to use google smtp server, but there is a limit of 500 emails a day, which is not very scalable.

I don't really know that much about sending emails and why/how they are blocked/considered spam. I'd appreciate any good advice/tips you can give me.

There is a way track if mail has been bounced (there are more than 10 possible bounce reasons!). You can set the return-path header in your outgoing emails. Best practice is to specify a different mail address in the return-path. When e-mails are getting bounced for whatever reason, a notification will be sent to this address. Additionally you can have for example a (PHP) cron job that connects using IMAP to the bounced email account and do something with the bounced e-mails. This is a pretty reliable way to track the status of your sent emails.

Additionally, in order to minimize the chance your e-mail will get blacklisted you could think about signing your e-mails using a certificate (you can get one for free for personal usage. A commercial one may cost you around 25 dollars a year)

2) What is a good way to test to see if the email portion of my app is working without installing it on my live server. Can I just setup an smtp server on my desktop and send mails this way? Can you recommend any other good ideas for testing. I'll basically be sending just a few emails to my personal webmail accounts to make sure that everything works.

You can actually send a test email from everywhere as long as the outgoing SMTP port (25) is not blocked. If you have an own smtp server with username/passwd authentication enabled, you will be able to send e-mails from everywhere using the these credentials/settings. In all other cases, you will have to use the smtp of your internet provider to send emails.

Answer 3

For email testing I use Pappercut. It's easy to use but some antivirus may not like you opening port 25.

Answer 4

I use Dumbster for testing. I will catch the emails, then my test code can check the content.

To avoid spam, there are a number of things you have to do, and I'm not sure I've found them all. Make sure that your IP is registered, and that a reverse lookup returns the right domain.