By default, we configure our system so that mails with a size of 20 MB can be received and sent. This is sufficient for classic mails including attachments such as invoices, general terms and conditions and revocation instructions. Mails with larger attachments cannot be sent or received. 

As a general rule, you should take care not to send large e-mail attachments. Even 20 MB is more than borderline. There are several reasons for this.

Size of the mails

E-mails are texts. Your mail must therefore always be converted into text before it is sent. This applies to your formatting as well as to your email attachment (keyword UUEncoding). Unfortunately, this leads to your email becoming significantly larger than your original files. Usually by a factor of 1.4, so if you send an attachment of 10 MB, the mail size will be at least 14 MB. These file sizes then have to be stored in your mail server, sent, saved by the recipient, etc. This wastes a lot of unnecessary storage space. Especially for mobile devices with paid traffic and limited storage space, this is a real problem.

Security

Mail size is also a challenge when it comes to security. Many virus scanners have a hard time with large file attachments and the system of your customers, but also your system (you also save the mails) often becomes noticeably slower. And this affects your PC, your mail server as well as your customer's mail server. This procedure is also often used to hack a system (keyword: mail bombing).

This is also an issue with TYRIOS, because the TYRIOS system is set by default to check all e-mails not only for SPAM, but also for viruses. The larger the mails, the more complex the procedure.

Solving the problem

So what is the best way to send larger attachments? Cloud storage providers have established themselves here in recent years. Some of these already integrate seamlessly into your email programme. This applies, for example, to

• Dropbox
• Google Drive
• Microsoft OneDrive

It is therefore best to upload the attachments to a cloud storage and add the corresponding link to your e-mail. You should do this for attachments of 5 MB or more.