Corporate Blog

As Christmas rapidly approaches, we’d like to remind you of two limitations to keep in mind with respect to sending email, and to implore you once again to take phishing scams seriously.

Sending limits

Within the last year or two we have had to implement a limit of sending to 300 email recipients per day per email account. This is a limit that hardly anyone runs up against, but it does happen. The reason for this is quite simple: email accounts are hacked when a computer or phone is compromised, and the person or organisation who has compromised the account then uses the account to send spam or phishing messages. If there was no limit on how many messages can be sent in a day they’d send millions! If this happens, our IP addresses are blacklisted and then none of our clients can send any emails outside of our network.

With this limit in place messages to only 300 recipients can be sent, and by the time the 24 hours are up a compromise will have been noticed, and the password for the email account can be reset. (We often notice these spam runs when they are in progress, and they are shut down before more than a few dozen are sent.) Experience has shown that if 300 such messages are sent, that seems to be just below the point at which damage to our IP addresses’ reputation is done. We experimented with a limit of 400, but damage was still done.

If you’re going to send messages to a few hundred or thousand of your customers we suggest the following:

• If you regularly want to send that many emails we strongly recommend that you use a company such as Mailchimp.
• If you have a one-time need to send a lot of emails, break your list up into groups of 300 (or just under 300) and send that many a day.

Please note that however you chose to send mass emails you must have documented proof that you’ve received permission from the recipients to send them non-personal emails like this. If you don’t have that permission, then don’t send them those emails. It’s quite simple. If you don’t have permission you cannot defend yourself against accusations of spamming, and you risk your account being suspended and removed.

Also note that the limit is the number of recipients. If you send an email to Bob, copy it to Jane and blind copy it to Jim, that’s 3 of your 300 recipients (not “1 message”). If you send another email to the same people, that’s now 6. If you send one email blind-copied to 300 recipients, you’re done for the day and you can go home. 🙂

Sending restrictions

We often see clients trying to send emails with restricted attachments. Our mail server stops emails with executable attachments (.exe files, for example, but there are more and it’s not the file name extension that determines if a file is executable) and documents that contain macros, or scripts that can be executed when the document is opened. These cannot be sent by email because they could contain malicious code. If you want to send these files to someone else we suggest that you either use what’s called the “sneakernet” — put the file on a flash drive and walk it over (perhaps wearing “sneakers”) to the person you want to give the file to — put the flash drive in the postal mail, or upload the file to a website or file upload service from where someone can download it.

Many office-type documents — spreadsheets, word processing documents, slide shows, etc. — contain macros (scripts), which you may or may not be aware of, and if you’re trying to send them they will not reach the intended recipient. Sometimes when you create a PDF file from an office document the scripts are embedded in the PDF, and those will be blocked for the same reason.

All email services — even the biggest ones — have these restrictions so that the email service as a whole can still be useful to the people that use it. If we don’t stop these kinds of emails from going out, the recipients’ mail servers will stop them from coming in.

Phishing

We desperately want to remind you yet again — we know, it sounds like a recording — about email scams, and in particular “phishing” scams. These scams happen. They happen to you. They happen to our clients. 2022 was a record year for our clients, and not a record to be proud of. Just among the clients we know of, over US$100 000 was lost as a result of phishing scams. This is shocking; this is heartbreaking. It doesn’t need to happen.

Treat every email you receive — even this one! — with suspicion. Rather than looking for signs that an email might be a scam, just assume it is! Then look for the signs that it isn’t a scam. Instead of memorising an interminable list of things to look for that show an email is a scam, instead simply ask the message to prove to you that it really is from the person who claims to have sent it, and that the request it contains is legitimate. Did NinerNet really just send you the email you received that is asking you to verify your email password, or upgrade to some service that we don’t even offer? No, we didn’t send that email. We just don’t send emails like that, and neither does any other mail provider … or bank, or life insurance company, or …. Almost nobody sends a legitimate email claiming that you have to pay an invoice in a different way to how you’ve been paying that company for years! Yes, your suppliers do change banks occasionally, but if they do they will give you plenty of notice, not send you a frightening message out of the blue demanding that you send them money to a different destination or have your service cancelled. It just doesn’t happen like that in the real business world. THINK! BE SUSPICIOUS!

You should learn more about email scams and phishing. Read these links:

• NinerNet blog on Scams
• NinerNet blog on Spam
• Wikipedia on Phishing
• Man-in-the-middle attack
  • This attack was used to steal about US$50 000 from one of our clients and their clients.

If you have any questions about any of the above, please do let us know. Thank-you.

We will have one more email for you before the end of the year, with information we’re excited about because we hope it will improve our email infrastructure in 2023. We hope you’ll like it too.