Mailguard - How to block many phishing e-mails
Are you receiving unwanted e-mails that are trying to look like they came from one of your internal users, but, those e-mails have a Reply-To: address that is outside of your domain? In most cases these are what is called phishing e-mails. Our E_NON_domain_REPLY rule-set can detect and block these e-mails.
Due to the potential for false positives, the E_NON_domain_REPLY rule-set is only enabled upon request. For this to be successful the following must be true:
- You are not white-listing your own domain.
- You don't have outside systems sending e-mail from your own domain with a Reply-To: address outside of your domain. If you do have outside systems legitimately sending e-mail from your own domain, you must let us know so that we can also take those systems into account.
To enable this rule-set, please contact us and request that we enable the E_NON_domain_REPLY rule-set for your account.
We Answer Your Questions: FAQ
Q: What is the maximum e-mail attachment size?
A: The ETRN.com e-mail servers do not limit the size of individual e-mail attachments. The ETRN.com e-mail servers do impose a 400 MB maximum total message size limit. Individual customers can choose a smaller message size limit. We can also customize the handling of "over-sized" e-mails. Please contact us to discuss your specific needs. A couple of important facts:
1. Attachments are typically encoded in what is called Base64[1]. As a result, the actual length of MIME-compliant Base64-encoded binary data is usually about 137% of the original file size.
2. E-mails often contain both plain text and HTML components. This also increases the overall size of the e-mail.