Learn Turkish: Şu an kurye güncel teslimatı gecikmeli ulaştıracak. - The courier must be delivering the current delivery with a delay right now.

This is the epistemic use of the future tense -(y)AcAk. Just like English speakers say 'He will be there by now' to express a logical deduction about the present, Turkish uses the future tense to show a strong assumption or expectation. Here, it translates to 'must be delivering' rather than a literal future action.

Why use ulaştıracak instead of the standard verb for deliver, teslim edecek?

Ulaştırmak is the causative form of ulaşmak (to reach), so it literally means 'to cause to reach' or 'to convey'. Because the sentence already uses teslimatı (the delivery) as the noun, using teslim edecek would sound highly repetitive (teslimatı teslim edecek). Ulaştırmak is a natural-sounding alternative to avoid repeating the root word.

Why doesn't the final 't' in teslimat soften to a 'd' when the accusative suffix -ı is added?

Many loanwords from Arabic ending in -at, like teslimat (delivery), hayat (life), or saat (hour), are exceptions to the Turkish consonant softening rule. Therefore, the 't' stays hard, giving us teslimatı instead of teslimadı. This is an important phonetic exception to remember.

Is gecikmeli an adjective or an adverb here?