Big ISPs only care of popular e-mail client programs, they will likely add a tutorial on their web site for a very few of them. They have no time nor resources to know of every product available so as a result they will simply tell you they don't support a program they don't know. Sometimes you will even be told they don't support 3rd party products although almost all e-mail programs are 3rd party products.
Also bear in mind most ISPs are for domestic uses. If you need to send bulk messages, maybe you should get a professional bulk e-mail account or an e-mail server like the one you get as part of any web hosting packages (Warning: web hosting companies may offer a paid web-based marketing service and discourage you to use MaxBulk Mailer using all kind of misleading arguments like 'it is a spam tool', 'it has no unsubscribe mechanism', 'it fakes headers' etc. MaxBulk Mailer is a bulk e-mail software (spam means unwanted emails), MaxBulk Mailer has an unsubscribe mechanism and doesn't fake anything. This is a marketing move, they just want to get more money from you and control what you do with their servers. We recommend you to contact the server support and send them to this page, next fill a complaint at the Federal Trade Commision).
We haven't found a single ISP causing compatibility problems with MaxBulk Mailer so far. MaxBulk Mailer supports all kind of authentication schemes, alternative ports and SSL. Most of the time you just need to look at your other mail software and copy the settings to MaxBulk to make it work. You can also use the tutorials your ISP has placed online, they are useful even when they talk about another product.
MaxBulk Mailer is a full-featured and easy-to-use bulk mailer and mail-merge software for macOS and Windows that allows you to send out customized press releases, prices lists, newsletters and any kind of text or HTML documents to your customers or contacts.
MaxBulk Mailer is fast, fully customizable and very easy to use. MaxBulk Mailer handles plain text, HTML and rich text documents and gives full support for attachments. With MaxBulk Mailer you will create, manage and send your own powerful, personalized marketing message to your customers and potential customers.
Thanks to its advanced mail-merge and conditional functions you can send highly customized messages and get the best results of your campaigns. You also have support for international characters, a straightforward account manager with support for all type of authentication schemes including SSL, a complete and versatile list manager, support for importation from a wide range of sources including from remote mySQL and postgreSQL databases.
MaxBulk Mailer is a software tool that you purchase once, no need to pay on a per-email basis to submission services!