Data uploads if more than 10 email addresses should be sent over to Cybacat for upload. On sending data over please check to make sure there are no guest.booking.com email addresses within your data, CybaMaila does not accept these as they are temporary email addresses set up to protect Booking.com's users. Only hotels are aware of these email addresses.
Also skim the data for misspelt email addresses or email addresses which are far fetched, this maybe a sign your users did not want you to have their actual email addresses, although they maybe asuming to come across, if email addresses are not valid, this effects your open rate, the more emails get rejected as the email address is unkonown, the less like your email will reach those who are generally interested in your email campaign.
All email clients do their best to protect their users from spam, which is why it is important to check all email addresses look valid and geninue, also making sure they are under appropiate tags, so they only recieve information on the topics they are interested in.
Something everyone should be aware of!
GDPR requires that all supplied data must also have the source of how this data was collected clearly stated in the document, without this source being legitimate, accurate to the tag and without permission, it will be against the law promote using the email addresses.
Please take the time to read this article https://litmus.com/blog/gdpr-what-europes-new-privacy-law-means-for-email-marketers