This might strongly harm your customer digital experience and leave a bad general impression. In addition, in many email clients, a large email body might be rendered just partially, and your recipient will see just parts of images or clipped content. Your recipients do not always have access to a high-speed connection, and a long-lasting message loading process might cause irritation. Rendering issuesĪnother aspect of large emails is their loading and/or rendering speed. So, the common recommendation is to keep email body size between 15 KB and 100 KB. In most cases, messages with a body over 100 – 150 KB trigger spam filters. Many tests by various providers prove the correlation between email size and deliverability. For example, Postmark allows the HTML and text parts each to be 5 MB, while Gmail clips the body of messages over 102 KB. Still, some providers have their own limits. Technically, there is no message body limit in the SMTP protocol. However, there is a list of common “anti-spam” rules, and the size-related points are at the top of it. You won’t find strict and ubiquitous criteria for spam detection. Taking care to create a message that will be successfully delivered to your recipients, you should also think of which folder it will go to, how quickly it will be delivered, and how happy your recipients will be.Īvoiding spam filters and targeting the main folder of your recipient’s inbox is one of the trickiest things in email handling. What else should you consider about the size of your email? Moreover, some ESPs like Postmark have additional limits for the email body size. Spam score and rendering issues are the most important. However, besides general deliverability, there are few more concerns related to sending large messages.
But it is still possible when you send numerous booking or order confirmations, for example. It’s a pretty rare situation when you need to send a mass email with large attachments. You can see that most email clients are capable of retrieving 20 – 25 MB of email data. TextBody and HtmlBody can each be up to 5 MB each Email clientĢ0 MB (10 MB for Exchange accounts), with up to 150 MB in Office 365 Limits for popular email sending providers and clients like Gmail, Outlook, Sendgrid, etc. If you work with a big database of email addresses to send transactional or marketing emails and don’t have such details about your recipients, you should follow a general rule: send messages that don’t exceed 10 MB. It is useful to know the allowance for your recipient’s incoming messages. limit to retrieve a message (your recipients’ mail system).įor example, if your email service is able to send messages up to 15 MB but the email recipient can retrieve messages only up to 10 MB, it’s obvious that your email should not exceed 10MB.limit to send a message (your email system).When preparing either transactional or marketing emails, you should consider two limits: This makes them candidates for DoS (denial of service) attacks: a huge amount of large messages can take the whole system down. Email systems usually use a limited number of ports to retrieve data. Points 1 and 2 on our list also lead to potential security vulnerabilities. This is why not only the message itself but also the inbox as a whole has its own limits. Email data should be stored on a server (either cloud or local). In addition, mail transfer agents often scan incoming data for viruses and other potential risks, which also takes resources and affects system performance. Most of the systems are not able to process multiple data sources at once. They deal with SMTP, which is a quite outdated protocol.
Email systems are not designed to transfer large volumes of data.
Best mac email clients with notification how to#
What are the common issues and errors related to email size and how to handle them?Īlso, we have implemented an email size limit for Mailtrap: let’s review how it works and how it can help you with testing your email deliverability.Įmail size limits are used for three main reasons:.How do the embedded images affect email size, spam score, and deliverability?.