Most of the Email marketing companies such Mailchimp, Sendinblue and Aweber charges you around 99$ onward for 10K mails per month. However if your email sending limit is more than 10K per day, then you need to signup to transactional mail services. Here are some of the services that you can try for the 10k mail sending option.
Mailgun has known for the delivery. And they have very low rates for mail sending. So this can be one option worth looking at. You can check the pricing for the 10K mails per day here.
Mailjet has very flexible pricing. But depending on your usage the price for large mail sending limits may vary. For example transactional emails are cheap but promotional one are pricey. Here is the pricing calculator to check out.
This service charges you $199.95 for 300,000 mails. This can make it easier for you if your budget is on that point. The mail delivery rates are very good too. I have found that sendgrid's mails bounce rate is rather low. And they have good anti spam score too.
Check the pricing here. https://sendgrid.com/pricing/
These three services allow you to send large number of mails per day depending on the plan you purchased. And the mails can be sent without having them to land on the spam folder. For that your mail has to pass some criteria.
These three managed hosting services allow you to host the software such as Interspire mail marketing service script. And then you can send the mails of more than 10K capacity that too on your own hosting.