I will leave here some suggestions to increase the open rate:
Check email list:

Get permission: Use double opt-in that requires new subscribers to confirm their signup, so you know they want to receive emails from you.
Include an update profile link in … (more)

Most likely this happends because of the spam traps. There are a lot of methods to detect and remove spam traps. One – no cost- method (only if you have a small email list) is to manually check your contacts and … (more)

I think the best way is through engaging content. Whether it’s a blog or a website you have to write a lot and keep your content upgraded. By engaging content, I refer to quality content or even games, contests, giveaways …
So, after … (more)

If you want to collect subscribers that are not opted-in, keep in mind that many of them are invalid. .So, If you want to send bulk emails (especially to bought lists), i strongly recommend using an email  validation system to … (more)

Hello,
The answers you already received are very correct. But you can fix this by checking the list to remove invalid emails. You can do this by using some email validation platforms in order to remove invalid emails, email complainers, pam traps and … (more)

A healthy list doesn’t always mean that it only brings you money. That is an advanced step and the content you provide could have a great impact on your revenue from the list.
The primary action is to analyze this KPI:
1. … (more)

There are many things  that may impact your campaign deliverability. From my opinion, the main issues are: invalid emails, email complainers, spam traps and missing data from your list. So, in order to increase your campaign deliverability you need to clean email list or listwashing.
Listwashing … (more)

First of all, you make sure that you are using duble opt-in that requires new subscribers to confirm their signup, so you know they want to receive emails from you. Double opt-in lists have better subscriber engagement levels over time. … (more)

Hello,
I am not very skillful with coding, so i had to use an email validation service.
There are a lot of free email validation platforms but these are not guaranteed 100% cleaning accuracy and are likely to be less well developed than paid … (more)

Hello,
If you have a large email list i recommend using an email validation system in order to reduce hard bounces, remove known email complainers and spam traps from your list and append missing data.
I have an 80k subscribers email list, … (more)