Why is the image in the letter 1x1px in Yandex?

Question

Yandex

Greetings.
When making up letters for mailing, I use two pictures. As a result, in letters sent to Yandex, I observe that one picture is not displayed (More precisely: (natural: 1 x 1 pixels) ). Letters for example in a mail perfectly show both pictures.
alt/width/height - available.
Size / name / format - everything changed. The result is the same - in place of the picture there is an empty space, and only Yasha has a campaign.
What can he not like about the image?

Answer 1

It was decided by appealing to Yasha.
Everything has been corrected.

Answer 2

antispam, antiphishing, etc.