SpamCheetah internals

SpamCheetah internals

What problems do MSPs face today? In 2021, Managed service providers (MSPs) face an email spam threat that can be broadly categorized as falling into several heads phishing time waste business email compromise viruses malware losing important mails when deleting spam and so on. Nobody likes to see email from unwanted sender or with unwanted content. But email being what it is, this will never be the case.

Continue reading The mail world - Mail servers, spam control and virus scanners

The mail world - Mail servers, spam control and virus scanners

Introduction to SMTP SMTP stands for simple mail transfer protocol and is documented in RFC5321 but it has been standardized some 30 years ago stared long long ago. Such a long time ago when Internet was just in its infancy and email was still being considered a hobby project. It is a text based project a la HTTP and it has only 5 or so commands. HELO/EHLO MAIL FROM RCPT TO DATA QUIT And the status codes also match the standard HTTP codes in what it means to have a 2xx or 4xx response.

Continue reading What is greylisting ?

What is greylisting ?

What is greylisting in SMTP? E-mail Spam has always been a problem that has been around ever since email came into being.variables Greylisting schematic From the above diagram it must be somewhat clear what greylisting is. This video will help you as well. Greylisting video Your browser does not support the video tag. What you can infer from above video is that the email is not accepted and a reject message is sent by the fake SMTP server process even before sending the E-mail body(the DATA command).

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