There are many cases where people receive spam emails containing no words, attachments, or links, and the purpose of these remains unclear.
Usually, spam emails contain random text snippets copied from technical, scientific, or news articles. The content could also contain a sequence of words with no meaning at all, and this is all part of spam filter avoidance techniques. The main idea is that an overflow of words and phrases confuses spam filters, allowing those words and phrases usually be picked up by such filters to be passed through.
In the case of “blank” spam emails, they do not contain any triggering words or phrases, and the emails do not even try to promote or sell something, so it is unclear how they are useful to spammers. However, there are some possible reasons for these seemingly pointless campaigns.
One of the reasons may be to identify email addresses. This will determine if they are active, and similarly, any inactive accounts can be removed from the spammers’ database. Any email addresses that return to the sender may be flagged automatically, and later removed from the spammers’ list.
Those emails also may be the result of a mistake, or the spammer may have forgotten to include the malicious link or attachment. Additionally, the link or attachment may have been removed by the software that the cybercriminal is using. Another possible reason for the empty emails is that the spam filter system may have removed the malicious attachment or link, though this action usually includes a notification indicating that content removal has occurred.