Technical reasons behind 0% open rate?

I sent an email to over 100 recipients and it has a 0% open rate. I am wondering if there is some kind of techincal issue that could explain this as it seems odd that out of 100 people not a single one would open the email.

Thanks.

Open rates are never 100% accurate for a variety of reasons. With a small sample of 100 emails, do you have any commonalities with that group such as using major email providers like gmail or is it a good mix of contacts? Also did you seed yourself in the list to receive the email to ensure deliverability? This is always a good idea so you can keep track of what your customers/prospects will see.

As far as technical obstacles go, with the free account you are limited with the options you have because emails are being sent on behalf of you by Hubspot. When you move to the paid accounts, you are able to use your domain and setup DNS authentication for DKIM/SPF records for your mail to authenticate and sign your messages to help improve deliverability as opposed to using a free account which does not offer that level of authentication.