Technology KnowledgeBase

Why does email get blocked or rejected?

There are many reasons why an email sent to a district account could be blocked (rejected) or delayed. The cause, of course, is that the message has something about it that matches what the mail filter sees in spam messages. Since the majority of our email from outside is spam (currently 65-70% of all of our incoming email is spam or junk mail), and since that spam tries very hard to mimic valid emails, it is a continuing problem that some valid emails either get blocked, or get delayed until a district staff person can review and approve the message (human review).

Below are the most common causes of this, and those that are most easily fixed.

Problem 1.  No Subject Line
Increasing numbers of parents and students are not bothering to put a Subject in their emails to staff, especially when attempting to send text messages to staff email accounts (since text msgs don't have a Subject). The lack of a Subject is a 99.9% match for spam, though, since we block thousands of spam messages each day that lack a subject. As a result, messages with no Subject are either rejected or held for human review. The held messages can be delayed for hours, even for an entire work day (if we have staff out sick).

Solution: Include a subject in the message and it will be processed MUCH more quickly! This is especially important for communications that need a response that same day. IF YOU RECEIVE A MESSAGE WITH NO SUBJECT, you can help future communications by adding a subject to the message when you respond.

 


Problem 2.  Large or Too Many File Attachments
Email is a poor way to send files, especially larger files (> 1 MB), even though it seems easy. A message that has only a file attachment and little or no text to the message (the Body of the message) will be marked as likely spam because thousands of spam messages a day include only an image file and not text as they attempt to get their message through in a way that mail filters can't scan. As with the "no subject line" match above, these messages may be rejected or held for human review, and the latter can delay the message for hours.

There are better ways than email to send files from a personal computing device or to receive them from students and parents. Details are available in KB Article 547

NOTE: If a parent or employee is trying to send in an official document such as a birth certificate, driver's license, or other document that could be used to steal their identity, PLEASE have them use MailFile to send the document. That avoids any permanent record of their document in our archives AND encrypts the file as it is transmitted to prevent it from being intercepted.


3. Mail Account Used by Spam Server
Many parents and students are finding out that their email account has been compromised in the past (someone stole their password or guessed it) and used by a spam server to relay spam messages to other people. When that happens and they send spam to our district staff, their email account ends up blacklisted (blocked).

Solution: If you have parents or students who's emails keep getting rejected by the district mail filter, this is the most common cause and the easiest to fix. You can send them to
http://www.nsd.org/BlockedEmailForm
and have them fill out the form there to let us know what email address has been blocked. We are often able to fix that the same day.

 


Problem 4. Sending from Common Spam Domains

If someone is sending email to you from a site that is commonly faked by spam, such as a bank, insurance company, package shipping company, major online retailer, or health insurance group, their emails may be delayed as the message is held for human review. The spam that mimics these sites is so good at imitating the valid emails that we often have to hold all messages from those sites to filter out those that are trying to steal ("phish") your personal information. The district has had over a dozen incidents in the last twelve months of staff accounts being compromised because someone fell for one of the spam messages that did get through. This affects companies like Bank of America, Wells Fargo, Amazon, Nordstrom (for us Northwest folks), UPS, Fedex, USAA, TIAA, Blue Cross, and (in the spring) Tax Preparation companies.

Solution: Parents who work for these companies are recommended to get a personal email account for communication with the district. If they have a cell phone or Internet access at home, they probably received an email account as part of one of those packages. There are also several free email service providers, including Google and Microsoft that can be accessed from any computer.

 


Problem 5:  Large signature for Real Estate, Finance, Home Business, or Advertisements

If parents or community members are sending email that always includes a large signature about their business, this can cause their emails to be rated as spam and blocked or held for review. This is common with financial institutions and real estate, where the signature may be many times larger than the actual message and mention keywords about their services. This is also common with staff who have a home business like Mary Kay Cosmetics, Scentsy, Stella and Dot, Southern Living, or Advocare.

Solution: In most cases, the problem is primarily when they send a very short message, so the signature makes up the large bulk of the message. Removing the signature solves the problem.

 


Problem 6:  Personal Messages and Spam Ratings

While the district does not specifically restrict personal email to district staff accounts, we also cannot do anything to assist it, per Washington State Code. Generally, short personal messages will go through without a problem. If the message covers topics that are not common in district work email, though, it may be marked as spam. Topics that commonly cause this are parties involving alcohol, gambling, vacation travel, financial topics and taxes, health care for the elderly or pets, home remodels/purchases, off-color jokes, and messages with language unacceptable in an elementary classroom. When an email is marked as spam, the mail account that sent it and those copied on it (excepting district accounts) may also get an increased spam score so that emails from them are more likely to be identified as spam. If it happens several times, the email address could reach the point where everything it sends is marked as spam.

Solution: If a district staff person needs to receive personal email messages during their work day for the district, they should have those messages sent to their own personal email account. The district does not block access to outside email services that can be reached using a web browser.

Parents who want to send personal messages to teachers or other district staff may find that they need to get personal email addresses from those staff to avoid having messages blocked, especially if the messages address any of the topics listed above.

 


Problem 7: Foreign mail servers and Newer Top Level Domains (.biz, .info, and such)

Our district has several families who use mail services from foreign countries and that may impact their ability to send email to the district. There are dozens of countries that, for various reasons, end up being common sources of large volumes of spam messages. All emails from servers in those countries end up getting higher spam scores, making them more likely to be blocked or held for human review.

There are also some parents who use domains set up in the newer Top Level Domains like .biz and .info, which were primarily used by spam services. Over 99.9% of the email we receive from those two example domains is spam, which makes other emails from those domains get scored higher as potential spam.

Solution: If this becomes a problem for a district parent or guardian, we can usually make a custom rule for that specific account to help offset the impact of their mail server's location or domain. Please use the Blocked Email Form to let us know about the problem.

 

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