Why can't I send large attachments or pictures?

MailMerge365 only allows you to send Emails with a total size (including all attachments) of 3MB. If you try sending an email with a larger size you will receive an error message response when trying to send that campaign.


  • The way MailMerge365 works is a copy of your original campaign mail is made for each recipient. Therefore if you add attachments to the original email, these will be copied for every recipient and your mailbox size will grow quickly.
  • Also it's generally not good email etiquette to send large attachments to recipients because it also causes their mailboxes to grow.
  • Last but not least, by adding the attachment, you lose the ability to track if someone opened that attachment.


For attachments (e.g. PDFs) or images simply host them on your web server/homepage or a file sharing service (e.g. WeTransfer or Jumpshare). Then add the links to your email like this for example:

Dear Alex, Last time we spoke you showed interest in ACME and I promised to send you our brochure. Have a look at what we can offer.

This way the email is small, can be read on mobile with no problems and when the recipient clicks on the link you'll see this in your campaign reporting.

Did this answer your question? Thanks for the feedback There was a problem submitting your feedback. Please try again later.

Still need help? Contact Us Contact Us