I'd ask everyone who posts files larger than 250 Kb to use external file hosts.
The hosting space for this forum is limited. I'll have to limit attachment space to 100 Mb, and I already deleted many of the outdated and larger attachments. If large pictures and other large attachments will still be posted, I'll have to impose size restrictions for all attachment types.
Discovery is a large forum, and attachments are posted every day here. Just remember that large ones should be posted elsewhere, and that the forum should not be used as a reliable file storage. Attachments that are several months old might be removed anytime necessary.