I have more than 8 years of experience with email marketing, i am sharing my work history below, i can help you setup your own server for sending email marketing campaigns but you need to gradually build your system and send such high volume of emails.
Please also let me know what is the ratio to B2C and B2B emails on your list?
Hi,
I totally understand what you have been going through, i can help you fixing this issue, please let me know is your email list is optin? to how many subscriber you send email and how many are B2C and B2B in your email list? if possible can you share your domain so that i could run some test on it to give you some idea?
I have more than 8 years of experience for email marketing, i have done email marketing using different email marketing applications like mailchimp,constant contact, campaign monitor,dadamail,sendy,interspire,mailwizz,madmimi for many years for my several clients, i also configured mailchimp with external SMTP server called mandrill when it was stand alone SMTP but now this SMTP is only available for transactional emails for mailchimp users only.
Besides my third party mailing services like mailchimp, constant contact,madmimi etc experience, i also have experience setting up mailserver using external SMTP's like SES, Sendgrid,mailgun,sparkpost etc with third party email application like interspire and mailwizz, i can configure SPF,DKIM, DMARC records to authenticate the email.
Regards,
Rehan Saleem