The classic e-mail protocol, developed several decades ago, did not initially provide for the transfer of colorful postcards. Today the situation has changed. Sending a postcard over the Internet has become as easy as posting.
If you are good at computer graphics, create a postcard yourself. If you wish, you can even send a hand-drawn postcard over the Internet by photographing or scanning it. Make a separate copy of the file, where the image is reduced from the original to about 800 pixels horizontally. The preferred file format is JPG. If you use PDF, DOC, SWF and the like, there is a possibility that the addressee will not be able to view the postcard while checking mail from a mobile phone.
If you are going to send a postcard by email, simply attach it to the letter as an attachment. Another way is to post it on any photo hosting site. Then it will remain in the body of the message to indicate the URL of the image or page with it.
If you are going to send a postcard through an instant messaging service, do not try to use the file transfer function built into such a service. It is not always efficient even when using official, let alone alternative clients. Use photo hosting.
If you are not good at computer graphics, drawing on paper, or photography, use the service of one of the many postcard generator sites. Find one of them using any search engine. Choose one or another ready-made template, add text. If the card is an image, just download it and email it as an attachment. If this is a SWF movie, you will have to send a link to the generated page with it.
Some email services have built-in postcard generators. In this case, just go to the appropriate page and follow the prompts.
Check if the site of the mobile operator used by the addressee has the function of sending MMS messages from the site. If there is such a function, there are usually many ready-made postcard templates on the corresponding page. Choose one of these templates, then proceed in the same way as when sending an SMS from the website.