Yes can. They will even combine with your savings accounts' treatpoints.

Not sure how's the calculation for savings account but it is very little for my case. So you can ignore it.

* 5% Weekend Dining Cashback for all dining spending with your Maybank 2 American Express® Card during weekends, capped at RM50 per month per Principal account in Malaysia.

* Earn 5x TREATS Points for all spend on your Maybank 2 American Express Card in Malaysia or anywhere else in the world.

* Earn 1x TREATS Points for every Ringgit spent on Maybank 2 American Express Card at Education Institutions, Insurance Providers, Utilities: Electric, Gas, Sanitary and Water, Petrol, EzyPay.

* NO TREATS Points will be rewarded for every Ringgit spent on Maybank 2 MasterCard/ Visa/ American Express card at Government Bodies

always spend using M2 Amex, M2 visa/master has been useless since day 1 

have you tried calling cs to unblock for online transaction?

did you inform the bank beforehand that you will be using it overseas?

My experience says its accepted worldwide.  Hence up till today, I can swipe at abroad without having call to inform.
But wondering why its different in your case.

It's accepted everywhere but make a habit to call banks before going to overseas. Else, after a few transactions, your card will be temporarily blocked and they have to call you for verification. Wasted more money due to roaming. I had this problem when I was in Japan, forgot to call and after second transaction went through, Maybank already called me.

So, I always encourage people to call before going to overseas. If in Singapore for few days, I won't bother.

To prevent fraud cases, Maybank has blocked online overseas gateway. Anyway, I don't need to call them to unblock for me.