Proton Mail: An encrypted email service based in Switzerland
Simple Login: Receive and send emails anonymously. With email aliases and many features for logging and evidence.
MEGA VPN: VPN sevice based in New Zealand
Strenght check (2IP) https://2ip.io/passcheck/
Password generator (Norton) https://us.norton.com/feature/password-generator
Email check (2IP) https://2ip.io/mail-checker/: To see if an email (still) exists
Email header analyzer (Google Admin Toolbox) : https://toolbox.googleapps.com/apps/messageheader/
Email IP check (2IP) https://2ip.io/know-email-ip/ : To find the sender's IP
https://haveibeenpwned.com/: Check if your email address is in a data breach
https://hackcheck.io/: Check if you have been compromised
Intelbase.is: Look up your passwords have been compromised
Anonimity check (2IP) https://2ip.io/privacy/
Fingerprinting https://coveryourtracks.eff.org/: check and understand your tracks
Random data by LAM Datasets: https://www.lambdatest.com/free-online-tools
Create Any Fake WhatsApp, Instagram, Facebook Chat and More: https://fakedetail.com/
Details generator (in bulk): https://www.fakenamegenerator.com/
https://www.lambdatest.com/free-online-tools/credit-card-number-generator : Credit Card details
Temp-mail.io: Protects your privacy and keeps your inbox spam-free (if its a one time thing that doesn't need logging)
Temp-mail.org: Protects your privacy and keeps your inbox spam-free
Receive SMS (multiple countries) https://veepn.com/online-sms/
Receive SMS: https://receive-smss.com/