Some minor adjustments to be made to our sites.

We have real estate sites that are developed in PHP. All the sites have had various works done along the way and some functionalities are not working properly anymore.
Main Objectives

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a) One of the main objectives of this project, is preventing the harvesting of personal data from the sites and block certain programs (example EMEX3) to gather data. This will have to be implemented throughout our sites and make sure it works.
b)Search Panel
The searches are not functioning properly as of late. This has always worked properly and still does, but when certain criteria are selected, the results shown is a list of items matching only one search criteria.
c) Uploading of Properties/Description
The main site is translated into 4 languages (English, Spanish, Italian and German). When some special characters are used in the description for specific languages (example: ñ, é, á, ú, etc.) they are not shown and instead they get replaced with all sorts of different characters. Also, the spacing and line breaks are not showing for certain languages and finally the photos are not showing for other languages.
d) Newsletter and Registered Users
These functionalities are in place on the main site but not working as they should:
-Registered Users do not get an email with their registration details.

-The data is stored in the database, but we need to get access to this data and be able to get email addresses.
Newsletter
There is a functionality in place, that basically sends over all the properties added in the month that match the search criteria selected when registering.

This has stopped working about a year ago and we can´t understand what is wrong.
Moreover we would like to have some advice on how to fire newsletters from the site, and upload email addresses as they were opt-in.

This functionality needs to be safe and not be seen as SPAM or affect our Web and Email Reputation Score being affected. Finally we need to make sure that emails/newsletter reach the receiver inbox and not the spam/junk folder.
On this point we require some advice and understand what would be the best way to implement this.

If accepted, we will change the structure of how the newsletter is fired.