Cannot send email via AquaMail Pro.

[mbo]

Recently, my AquaMail Pro app will not send email. I haven't changed any settings. I've had my email account for years and have also been using AquaMail without issue for around 8 months. I checked with tech support for my account and they could not find any issues. I can send mail from my account using other mail apps. I've attached the error message I receive. Anyone ever had this issue? 

[Kostya Vasilyev]

Over the last few days, I got emails from four or five users with same exact error message.

At least one of those users has same mail service as you do, the other ones didn't specify (I looked up the address in your profile... the mail service ends with "...one.net").

The error message comes from the server. There were no changes in the app (last update was end of Dec - start of Jan).

Please contact Support for this mail service.

[mbo]

I tried the help desk with my provider and they weren't able to help. Oddly enough, I just tried sending a mail and it worked. Definitely something on the provider's side, as I haven't changed anything in AquaMail. Thanks for the quick reply. It's not the first time I've had issues with the provider.

[Kostya Vasilyev]

My guess they might have blacklisted the app for some reason, based on its User-Agent, then removed after realizing that a promo signature ("Sent with AquaMail") is not really spam.

Glad to hear it's working again, though. I hate mysteries like this one.