By default on Sarbacane Suite, an email campaign costs you one credit per recipient.
Thus, a communication intended for 150 recipients will cost you 150 credits, provided that it does not exceed a weight of 194 KB.
In certain cases, it is possible that at the time of sending, this cost may be higher than the number of recipients you have imported.
To ensure that your message does not exceed this limit, you can go to the Verifications section of your account, then select View Summary :

Here, we can clearly see that this sending will require 4 credits per recipient:

The increase in the number of credits can come from several causes that we will detail below.
When you create your campaign with Sarbacane's EmailBuilder, you have the option to benefit from 5 MB of image hosting per campaign. This allows you to import a large number of images, GIFs, screenshots, etc.
This option corresponds to the cloud space available in your campaign settings from the "Message" tab, then "Advanced Configurations" and finally "Image Hosting".

You can already see the storage used here. By clicking on the "Image Hosting" button, you will be able to see in detail the hosting and weight of your images. This article will help you better understand the types of hosting.
Warning: If you wish to include your images directly in the body of your message, this is entirely possible, but in this case, the weight of each of your images will be counted, significantly increasing the cost of the campaign.
An attachment is an additional element to your email that can quickly become very heavy. The cloud space we provide does not allow hosting attachments. We therefore recommend that you host your attachment on a dedicated space and then include the access link directly in your message.
This article presents the additional risks associated with adding an attachment to your email.
Dense content with extensive formatting (bold, varied colors, different fonts) increases the HTML code weight, thereby increasing the message size.
Duplication can cause unnecessary accumulation of content, particularly in the text version.
If you do not take care to clean up this version, the overall weight of your message increases.
This is why we advise against duplication.
An overly heavy message presents several disadvantages:
Additional Cost: more credits consumed.
Deliverability Risk: anti-spam filters and server security systems more easily detect large emails, which may impact their proper reception.