On the technical side 01-17-2017
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ADCC / NKC Systems Inc.

Computer Repair & Consulting Services

On the technical side 01-17-2017

Have you ever been unable to send an email to someone or had someone tell you that they are not able to send you email? Your email program is configured properly because most of your email is sent or received. Why do some email addresses refuse to be sent or received?

Send email problems are usually pretty easy to notice. You send an email but a short time later, you receive a bounce notice. The bounce message will usually provide enough information to identify the problem. The majority of failed send messages is an improperly typed address. If the address isn’t correct, it can’t be delivered.

If the address is correct, the most common cause of failed sent email is the dreaded blacklist. Since spammers have inundated the Internet with spam, different schemes have been used to reduce spam. One method is blacklisting. About 50 companies have created lists of emails that have originated spam. The lists are updated continuously and used by spam filters to block any blacklisted email addresses. 

Blacklisting seems like an easy solution but it has caused a lot of valid email to be discarded. Spam wasn’t a consideration when email was first developed but spammers have determined how to mess up a good thing. If a customer at a particular domain.com generates spam, everyone with a domain.com address will be blacklisted. Even though you have never sent spam, your email is classified as an entry in the blacklists because you have a domain.com email address. Some big servers have a range of ip addresses to send email. Your email might use a good ip address during one send but a bad address during a later send operation.

Many first level ISP, Internet Service Provider, service personnel don’t even understand how blacklisting works. You can call your ISP and complain that your email doesn’t arrive. If you report that your ISP email send server is blacklisted, the service person may not understand the concept. Blame the customer seems to be the common response.

“Your computer has a virus…” seems to be the cause of all computer problems. Viruses are mysterious things that most people don’t understand. It is easy to use the virus excuse. Many “virus” problems aren’t really even viruses. The computer might be misconfigured or have a lot of unnecessary programs but some troubleshooting should be done before declaring that the computer is infected with a virus.

If the sender’s email address is listed in a blacklist, you won’t receive email from that particular address. How can you tell something is wrong? The sender has to notify you that they sent email. It is the sender’s responsibility to troubleshoot send problems.

Email usually works well but intermittent email problems can be extremely difficult to resolve


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ADCC /NKC Systems Inc.

1794 Bridge st ~ unit 8A

 Dracut, MA 01826


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