Why are emails being rejected by some companies?

You will agree that spam is the scourge of the business community. Millions of dollars are being spent in the protection of employees from becoming infected with rouge emails.
While the text of an email is analysed, the Internet address it came from is checked on several “black list” databases, the structure and form of the email is also examined to check its validity.
However, there is a much simpler test that your outbound email server is failing when sending emails. The problem is your company’s domain Sender Provider Framework or SPF information is incorrect and putting your emails at risk of being bounced.
When your IT setup your emails they would have set up a SPF record for your domain. A SPF record is simply the Internet addresses (IP) that this sending email server owns. Therefore, the sending email server is saying which IPS are allowed to send on behalf of your company.
The way it works is as follows:
  1. The receiving email server looks at the domain name the email address came from, e.g. @netech.biz. It pairs this with the IP address the email came from.
  2. The receiving email server takes this domain name and asks the domain name to provide its SPF record.
  3. The receiving email server then verifies that the IP address listed in the SPF record matched the IP address examined in step 1.
  4. If there is a match then the email continues on its way.
  5. If there is no match the receiving email server has no way of verifying the IP address the email came from. It rejects (bounces) the email with a 550 code to the sending email server. This code is interpreted differently across mail servers but can be, spam, user not found, mail failure or unknown.
You are receiving this bounce back because you SPF is incorrect. There is nothing wrong with the receiving server, it is just trying to verify the address the email came from and cannot.
The SPF standard format is not checked by all receiving email servers but the ones that do will keep rejecting your emails. This standard has been around since 1982 and should be well understood by your IT and email provider.
You urgently have to ask the question of your IT staff and email provider to correct the SPF record for your domain. There are plenty of tools on the Internet to get an instant response on the validity of your SPF credentials. Just go to Google and enter “SPF check”.