Use Invisible Hashtags to Track Emails

Invisible Email Hashtags

Did you know you can create invisible hashtags that enable you to categorize and track Emails?

I recently read a neat little trick on the Zapier Blog on "creating invisible hashtags” in your Email.

The way it works is that you enter a custom hashtag at the bottom of your Email. You then select the hashtag and change it into a “white font”. This renders the hashtag invisible to the email recipient. The white text is not visible against the white background of the email message!

So, why create invisible hashtags?

They allow you to categorize and track your sent Emails. You can also track replies to your Email s as well.

And you can do all this without the sender knowing that you are tracking the Emails.

Here is an example:

Let’s say you want to ensure you are able to always find Emails about a sensitive customer project called “Orion”.  

Whenever you create an Email related to project “Orion”, you put “#Orion” at the bottom of the Email and change the font to “white”.

When you want to search for Emails related to project "Orion", you can just Search for the keyword “#Orion”. Your mail search will find these Emails, even though the font color of the text is white. Luckily, text searching doesn’t care about font color or font style!

This also will allow you to track the "replies" to your Emails that contain your invisible hashtag. The reply will also contain that invisible hashtag as well.


Here are some other ideas about using invisible hashtags:

You can create a simple Outlook Rule for incoming Emails that contain your invisible hashtag. Your Outlook Rule can move the Email into a separate Email folder. Or perhaps keep it in your Inbox, but mark it as "high" importance. You can even set it to a custom color or font for easy identification.  

For Outlook users, you can automate this process by creating an Outlook Quickparts with your invisible hashtag. This will make it very easy to add it into your Email in a single, simple step. No need to type it and turn the font color to white. Outlook Quickparts can do all this for you automatically!

Another approach is to add the invisible hashtag to a custom signature. This is easy to do, since Outlook allows you to create choose from multiple Email signatures. Just make sure to always use the signature containing the appropriate invisible hashtag and you are all set!


I have never used invisible email hashtags myself, and this was a new idea for me.

Using invisible Email hashtags is certainly an interesting and creative approach. So, I wanted to present it here since there may be cases where this could work well with your own individual Email processing routines.
— Michael Einstein

I do use Email Subject Line hashtags, and highly recommend everyone makes use of them!

Have you ever used invisible hashtags in your Email processing routines?

If so, what do you use them for?