Best practices for sending large attachments with OCI Email Delivery

April 18, 2022 | 2 minute read
Dickie LaFlamme
Senior Deliverability Specialist
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Oracle Cloud Infrastructure (OCI) Email Delivery enables customers to send bulk and triggered emails, including with attachments up to 60 MB. While this option is great for some senders, sending such large emails with attachments is something to avoid.

Unlike personal correspondence, bulk, transactional and triggered email was never designed to have attachment values. This decision requires massive throughput, depending both on the size of the attachment and the number of recipients. The ability to have enough throughput to send a PDF to an individual or small group of people is great. However, sending emails with attachments to mass audiences can harm your sending reputation with possible latencies or mailbox denials because of size restrictions, defeating the purpose of sending at all.

A better solution

Our best recommendation is to host the documents that you want to attach and share the link to the file in the body of the email itself. This configuration creates a cleaner user experience with a simple click to retrieve the information and avoids any throughput issues. The receiver can then also add the link to their browser’s bookmarks, negating the need to save an attachment or depend on local file storage.

For hosting these PDFs or other email attachments, we recommend OCI Object Storage, a one-stop shop solution. With Object Storage, you can host attachments, determine your authentication method (whether to require an OCI account to access or have the asset publicly accessible), and include links to these files in the body of your emails.

Then, when sending files, you only need to be concerned is the actual delivery of the emails. Luckily, if you’re properly set up with SPF, DKIM, or DMARC authentication, and sending emails to users that are expecting to receive them, any potential issues are mitigated.

You have options

Large message sizes do have their place for one-off use cases, which is why OCI Email Delivery supports large attachments. However, when senders are sending many large messages regularly, we highly recommend going with a more sustainable method that adheres to industry best practices.

Every use case is different. The only way to know if Oracle Cloud Infrastructure is right for you is to try it. You can select either the Oracle Cloud Free Tier or a 30-day free trial, which includes US$300 in credit to get you started with a range of services, including compute, storage, and networking.

For more information, see Oracle Cloud Infrastructure Email Delivery.

Dickie LaFlamme

Senior Deliverability Specialist

A Deliverability Geek by day and avid outdoor enthusiast..also by day. I work on OCI's Deliverability team for the Email Delivery product. I have many years of experience consulting with customers about their email programs and how to effectively deliver mail.


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