Mailchimp never required me to have an OTC for importing a CSV file of new leads. I don't see why that layer of security is needed when I am already logged in with two-step authentication, and it can cause problems.

One problem, for example: Last week I was unable to import new email addresses before sending an Email Broadcast because to the Zenler OTC / OTP* was going into a junk folder in my webmail, which has never happened before.

(*it's called One time Passcode on the screen but OTC in the email that should arrive)

In my case, I use Google workspace for managing multiple email addresses and have for years. The OTP from Zenler had arrived just a few days earlier without problem during a previous import to my secondary site. Zenler Support kept telling me to check my email junk folder, and i checked my google workspace multiple times but it was never there. I had to log in to my website's hosting account, go to their webmail service (again, it had been years since i needed to check there) and eventually I found the codes in that webmail.

As far as I can tell, something changed in the "score" of the Zenler OTC email from address, i.e. it had been marked as spam or junk more than once by someone or some bot.

This may be an unusual case, but the point remains: why do we need an OTC for such a simple task? You can change the homepage, or delete entire courses or modules without that layer of security.