I'm building an app to allow my users to send email. I want the email to originate from their domain. Currently, email is sent on behalf of my Mandrill account with their name/email used for the From header. It "works" but most of the mail is not delivering as best as I think it could.
The way I see it, one option is to use a service like Mandrill, Mailgun, Sendgrid, etc and have my users update there TXT records to verify their domains, thus allowing me to send on behalf of my users. Is that correct?
I'm wondering if another option would be to collect SMTP credentials, and then send the message via SMTP for my user, thereby preventing my user from having to log in and update their TXT records before using my app to send messages. I think it would be far easier to simply add SMTP credentials. Is this possible?
"The way I see it, one option is to use a service like Mandrill, Mailgun, Sendgrid, etc and have my users update there TXT records to verify their domains, thus allowing me to send on behalf of my users. Is that correct?"
Correct you'll want them to minimally have an SPF record that says the service you use is allowed to send email for the domain. I.e. TXT v=spf1 +a +mx inlcude:sendgrid.net ~all
"I'm wondering if another option would be to collect SMTP credentials, and then send the message via SMTP for my user, thereby preventing my user from having to log in and update their TXT records before using my app to send messages. I think it would be far easier to simply add SMTP credentials. Is this possible?"
Not really. They'll need to make sure their DNS records minimally have a valid SPF (TXT) record, otherwise the major email providers and players will either drop their messages or mark them as SPAM/junk.