I am using Apex to send emails with attachments to users.

For incoming emails, I know the maximum size of the email, including the attachment, is 10 MB. Email which are above 10 MB are not processed by Email Services and are rejected with an email response back to the sender.

However, I am having trouble determining the maximum size for outgoing emails. I've heard there's a 3 MB limit but haven't seen this documented.

  1. Can you all confirm an outgoing limit on email or attachment size?

  2. What happens when the limit is exceeded? What kinds of errors would I see?

  3. Is there any way to send emails more than this limit without leveraging any appExchange tool? Any ways?

Thanks in advance.

  • Where did you get the 3MB figure? developer.salesforce.com/page/… has 5MB limit per attachment for incoming attachments.
    – Benj
    Mar 27, 2015 at 18:52
  • Benj - you are talking about email services that handles inbound emails. I am concerned about outbound email attachment size. Mar 27, 2015 at 18:55
  • I know - that's why I posted as context in a comment, not an answer. I've just never heard or seen 3MB before, and was explaining a number I have seen.
    – Benj
    Mar 27, 2015 at 18:57
  • Please navigate to "usage" section. Mar 27, 2015 at 19:01

4 Answers 4


According to my R&D outgoing email attachment size 5 MB but still some issue if we have to attach more then 3 MB file it send but it converted in .html.In Spring '15' Release note also not define the outgoing email attachment size. I think attachment size depending on different 'Salesforce Edition' which you have use.

Email to Salesforce For all editions:

• Email body truncation size: 32 KB
• Maximum number of email activities created for each email received: 50
• Maximum size of a single file attachment: 5 MB
• Total maximum size of file attachments: 25 MB

Above point Email to salesforce but you can see in also in following link and not specify limit for email service.

https://ap1.salesforce.com/help/pdfs/en/salesforce_app_limits_cheatsheet.pdf https://help.salesforce.com/HTViewHelpDoc?id=limits_email_general.htm&language=en_US

If you have have use other third party tools like Mandrill Email Service then you can use more size of attachment compare to salesforce.

I hope this might be useful for you if i wrong then please correct me.

  • @DK - Yes you are right. I tried to send attachment of more than 3 MB and it converted to htnl format. I am digging depper into the issue to find a way to send attachments. I ll let you know when i find something substantial without using any appExchange tool. Thanks. Mar 11, 2015 at 6:51
  • For emails with attachments larger than 3MB, they are stored on a temporary CDN for 30 days. The HTML file should cause the file to download in most clients.
    – sfdcfox
    Mar 27, 2015 at 19:12
  • I'm a bit confused about the limit because when I try to add an attachment to an outgoing apex email inside of our Salesforce community, I get an error if it's over 2 MB, not 3 MB. Is the limit different for apex emails or when sending from a Salesforce community?
    – Rochelle
    Apr 24, 2015 at 17:37

Yes there is a limit from salesforce side for sending large size attachement.You can overcome this limit by using 3rd party storage server for storing the file content as well as sending them over the email with large size attachment. Cloud Drop is One such App that is some what following the same logic in order to store any number and size of files that can be associated with any salesforce object with Rackspace server.It also allow user to send very large size file as email attachment to particular contact/lead record. Please check the following link for more information:



Using salesforce version "Spring '20 Patch 12.9" , Unlimited Edition

Even SF mention that this idea was delivered , but it still did not work properly. I tested and confirmed that the 3MB mean single outgoing mail TOTAL attachment size


1) 2.99MB single attachment on single outgoing mail. Result work good , file can download as attachment

enter image description here

2) 2.8MB , 0.1MB , 0.15MB multiple attachments on single outgoing mail . Result work bad , file cant download as attachment and auto convert to SFDC html template with some link enter image description here


To fix 3MB Salesforce outgoing email attachments auto convert to html hyperlink issue , you need to

1) Make sure your saleforce server instance is version SPRING 17 or above , get this info using https://status.salesforce.com/

2) then go to Setup > focus Quick Find box > key in Email attachments , tick the option: "Include as attachment up to Salesforce email size limit or as links if more".

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .