Quotas
Once you sign-up on this site, it will take some time before you hear from them. However, if the company has any opening in Belgium, you will be notified by email and asked to confirm your participation.
Feedback: I am a current participant in one of Quota's mail surveys. The job is easy as you just have to input the test letter with the code and the transponder number you receive on time (within 2 days). You have to inform management of any upcoming holidays so that they will suspend posting test letters during your absence. There are also transponders that you need to send back in self-addressed, paid envelopes, so this is at zero cost to you. Plus, I have a postal box a few meters from the house where I can drop transponders to send back to Germany.
From time to time, there are special projects launched where you can earn extra money, so watch out for these. At the moment, monthly payment is reduced from €10 to €5.
Hauser Group
Quite popular in the US, it is not easy to sign up for this company. However, I got the sign-up page to work and is awaiting verification from the company.
Update: It seems there is no word on Hauser until now which means that they do not need mail agents in Belgium at the moment.
US Monitor
You get paid to receive mail from clients in Europe and even the US. Each piece is worth $0.25 and there is a fixed monthly fee of $10.00. The more test letters you get, the more you'll earn. Sign-up to be a decoy agent no matter where you are located. If there is an opening or project in your country, US Monitor will contact you.
You will receive practice letters to see how well you can follow instructions. So, don't go opening a mail coming from them immediately. You will know it's from US Monitor because they use strange decoy names. Log-in to your agent account and make a mail entry and wait for instructions. That's when they tell you where the code is located and if a pop up window appears, take the number down and write it on the test letter. This has to be sent back to the US without charge to you. Well, apart from the local call to UPS when you schedule a booking that's gonna cost you €0.25.
Beforehand, someone from US Monitor will send you pre-printed labels that you give to the UPS guy. Ask for envelopes, too as you'll be expected to send back at least 30 pieces of mail. They pay by check monthly.
