Tips for sending valid emails from your Recruitment Website

Posted By: Thomas Shaw, 1:24am Monday 01 February 2010

Most recruitment websites have some sort of online form capabilities - contact form, online timesheet, job order, newsletter signup form, email to friend form, online application form, etc. But could these emails be going directly to the users junk/spam folder or just never reaching the inbox in the first place?

Although it is not always possible to detect the reasons for this, there are several things you can do to minimise the risk. Here is an adaption of an interesting blog post I tweeted last week Tips For Sending Valid E-mails From Websites.

Send emails through a valid email server with authentication

It is a good idea to choose website software that sends your emails through your email server (this will require authentication rather than the web server's SMTP server). Servers that are specifically set to send emails generally have Reverse DNS & SPF records, support greylisting, etc.

There should be no excuse why you are not able to implement this on your recruitment website, as every scripting language offers different methods to send emails with authentication.

On the other hand, sometimes just using email servers is not good enough. You may need to send lots of emails but the hosting provider may be applying limits. This is often the case when you use cheap or shared hosting providers.

Reverse DNS (rDNS)

As every domain resolves to an IP address. Optionally, IPs can resolve to domain names which are called reverse DNS. Many spammers use non-existing or dynamic emails without reverse DNS records. Email servers generally check if the sender IP has a reverse DNS record or not.

How do you add reverse DNS records? Reverse resolving uses the pointer DNS record type (PTR record) which you should be asking your hosting provider to create it or check if it exists.

SPF Records

Sender Policy Framework is being used by more & more email providers everyday (Gmail, Hotmail, Yahoo, etc) as a criteria to detect if a message is spam or not. It simply allows the owner of a domain to specify their mail sending policy (like which mail servers they use to send mail from their domain).

SPF records are DNS TXT records which an online setup wizard can help you creating it (you'll need to create new DNS records).

Using a SMTP server that supports greylisting

A very powerful spam prevention method used by mail servers is called greylisting. When you send an email, the server receiving it can say to your SMTP server "send it to me again in x minutes" which is mostly not supported by the methods spammers use.

So, you need a smart SMTP server who can understand this command that will re-send the e-mails when requested.

No bulk mailing

Both the SMTP server you'll be sending emails and the servers that will receive them generally have rules to define an IP/email as spammer who sends x number of mails in Y seconds. So, if you have a large database to send emails - it will be a good idea to send them in intervals.

Do not send emails in alphabetical order

If you are sending emails to a large database, don't send them in alphabetical order as mail servers can mark them as a dictionary attack.

Check if the server IP is blacklisted

Blacklists are systems that are used by most of the email service providers. It has bot and human email accounts which analyze the common email traffic and can blacklist IPs according to emails sent from them.

The server you're using to send e-mails can be shared by many other users. If spam is sent by anyone on that server can lead to a "blocking" by email blacklists which will damage the communication of every account on it.