I have to find a solution to send an email to a customer database (11,000 contacts) but each recipient will receive a unique attachment as it’ll contain their account number and special pricing.
I know Marketo doesn't support attachments in emails but does anyone know of another way to achieve this?
Kind of impossible to answer! If it must be an attachment, it can't be through Marketo. If it must be through Marketo, it can't be an attachment.
The only way to vaguely approach this is to gateway your Marketo emails through a dedicated SMTP server that attaches the file before relaying the email. We had to do this once. It was not, by any stretch, easy and was only possible b/c I used to be a mail admin. Otherwise you'd have to have very savvy + willing IT.